mAi: #108 - t-paliad-276 submission generator language selector (DE/EN)

Per-draft `language` column drives the .docx output language for the
submission generator. The lawyer picks DE or EN on the draft editor's
sidebar; the generator selects the language-matched template variant
(falling back through {code}.{lang} → {code} → _skeleton.{lang} →
_skeleton → letterhead) and resolves language-aware variables
({{procedural_event.name}} → name_de vs name_en).

Schema (mig 130 — bumped from 129 to deconflict with atlas's #96):
- paliad.submission_drafts.language text NOT NULL DEFAULT 'de'
  CHECK IN ('de','en'). Existing rows inherit 'de' via the default,
  preserving every legacy draft's behaviour byte-for-byte.

Backend (Go):
- SubmissionVarsContext.Lang overrides the user's UI lang. Build()
  uses it when set; falls back to user.Lang otherwise — Slice 1's
  format-only /generate path keeps working unchanged.
- SubmissionDraftService.BuildRenderBag now threads draft.Language
  through. Create/EnsureLatest seed from the UI lang (DE default).
- DraftPatch.Language landed; Update validates and rejects values
  outside {de,en}. Project-scoped + global PATCH endpoints both
  surface the field.
- resolveSubmissionTemplate(ctx, code, lang) replaces the lang-less
  predecessor. Returns the matched tier (per_code_lang / per_code /
  skeleton_lang / skeleton / letterhead) so the editor knows whether
  to surface the "Fallback: universelles Skelett" notice.
- fileRegistry registers the EN skeleton sibling (`_skeleton.en.docx`)
  alongside the DE one; per-code EN variants land in a parallel
  submissionTemplateENRegistry (empty for now — EN templates land per
  HLC authoring). 404s from Gitea fall through silently.
- /api/projects/{id}/submissions/{code}/generate accepts
  `?language=de|en` query override (one-shot path, no draft row to
  pull the column from); defaults to the user's UI lang.

Frontend (TS/JSX):
- DE/EN radio above the variables list in the draft editor sidebar.
  Switching the radio PATCHes `language` and the server returns the
  freshly-resolved bag + preview HTML so the lawyer sees EN values
  immediately.
- Fallback notice ("Fallback: universelles Skelett (keine
  sprachspezifische Vorlage)") shows when the resolved tier doesn't
  match the requested language.
- 4 new i18n keys (DE + EN) + CSS for the toggle.

Tests:
- normalizeDraftLanguage covers DE/EN/case/whitespace/unknown.
- addRuleVars language-pick test pins procedural_event.name and the
  rule.name alias to the language-matched value.
- languageFallback truth table covers all 10 (lang × tier) combos.

Build hygiene: go build/vet/test clean; bun run build clean.

frontend/src/client/i18n.ts

@@ -1498,6 +1498,11 @@ const translations: Record<Lang, Record<string, string>> = {
     "submissions.draft.import.button": "Aus Projekt importieren",
     "submissions.draft.parties.title": "Parteien",
     "submissions.draft.parties.hint": "Wählen Sie aus, welche Parteien im Schriftsatz genannt werden sollen.",
+    // t-paliad-276 — DE/EN language toggle on the draft editor.
+    "submissions.draft.language": "Sprache",
+    "submissions.draft.language.de": "DE",
+    "submissions.draft.language.en": "EN",
+    "submissions.draft.language.fallback_notice": "Fallback: universelles Skelett (keine sprachspezifische Vorlage).",
     // t-paliad-240 — global Schriftsätze drafts index page.
     "submissions.index.title": "Schriftsätze — Paliad",
     "submissions.index.heading": "Schriftsätze",
@@ -4566,6 +4571,11 @@ const translations: Record<Lang, Record<string, string>> = {
     "submissions.draft.switcher.label": "Draft",
     "submissions.draft.name.placeholder": "Name of this draft",
     "submissions.draft.preview.title": "Preview",
+    // t-paliad-276 — DE/EN language toggle on the draft editor.
+    "submissions.draft.language": "Language",
+    "submissions.draft.language.de": "DE",
+    "submissions.draft.language.en": "EN",
+    "submissions.draft.language.fallback_notice": "Fallback: universal skeleton (no language-matched template).",
     "submissions.draft.preview.hint": "Read-only preview — final formatting in Word.",
     // t-paliad-277 — import-from-project + party-picker.
     "submissions.draft.import.button": "Import from project",

frontend/src/client/submission-draft.ts

@@ -20,6 +20,9 @@ interface SubmissionDraftJSON {
   submission_code: string;
   user_id: string;
   name: string;
+  // t-paliad-276 — per-draft output language ("de" or "en"). Drives the
+  // template-variant lookup and language-aware variable resolution.
+  language: string;
   variables: Record<string, string>;
   selected_parties: string[];
   last_exported_at?: string | null;
@@ -56,6 +59,11 @@ interface SubmissionDraftView {
   has_template: boolean;
   template_missing?: boolean;
   available_parties: AvailablePartyJSON[];
+  // t-paliad-276 — template-tier metadata used to surface the
+  // "Fallback: universelles Skelett" notice when the requested draft
+  // language has no per-firm language-matched template.
+  template_tier?: string;
+  language_fallback?: boolean;
 }
 
 interface SubmissionDraftListResponse {
@@ -411,7 +419,7 @@ async function fetchGlobalView(draftID: string): Promise<SubmissionDraftView> {
   return resp.json();
 }
 
-async function patchDraft(payload: { name?: string; variables?: Record<string, string>; project_id?: string | null; selected_parties?: string[] }): Promise<SubmissionDraftView> {
+async function patchDraft(payload: { name?: string; variables?: Record<string, string>; project_id?: string | null; selected_parties?: string[]; language?: string }): Promise<SubmissionDraftView> {
   const p = state.parsed;
   if (!p.draftID) throw new Error("no draft id");
   if (state.inFlight) {
@@ -463,6 +471,8 @@ function paint(): void {
   paintNameRow();
   paintImportRow();
   paintPartyPicker();
+  paintLanguageRow();
+  paintLanguageFallback();
   paintVariables();
   paintPreview();
 }
@@ -703,6 +713,64 @@ function formatStamp(iso: string): string {
   return d.toLocaleString(isEN() ? "en-GB" : "de-DE");
 }
 
+// paintLanguageRow syncs the DE/EN radio with the loaded draft's
+// language. Switching the radio fires onLanguageChange which PATCHes
+// the draft and lets the server return the freshly-resolved bag +
+// preview HTML (so the lawyer sees the EN form names appear without a
+// manual reload). t-paliad-276.
+function paintLanguageRow(): void {
+  if (!state.view) return;
+  const lang = (state.view.draft.language || "de").toLowerCase();
+  const de = document.getElementById("submission-draft-language-de") as HTMLInputElement | null;
+  const en = document.getElementById("submission-draft-language-en") as HTMLInputElement | null;
+  if (de) {
+    de.checked = lang === "de";
+    de.onchange = () => { void onLanguageChange("de"); };
+  }
+  if (en) {
+    en.checked = lang === "en";
+    en.onchange = () => { void onLanguageChange("en"); };
+  }
+}
+
+// paintLanguageFallback shows / hides the "no language-matched
+// template" notice. The server sets language_fallback=true when the
+// resolved template tier doesn't match the draft's language
+// (e.g. EN draft → DE per-code template, or no skeleton EN sibling).
+function paintLanguageFallback(): void {
+  const el = document.getElementById("submission-draft-language-fallback");
+  if (!el) return;
+  const fallback = !!state.view?.language_fallback;
+  el.style.display = fallback ? "" : "none";
+}
+
+async function onLanguageChange(lang: "de" | "en"): Promise<void> {
+  if (!state.view) return;
+  if ((state.view.draft.language || "de").toLowerCase() === lang) return;
+  setSaveStatus(isEN() ? "Saving…" : "Speichert…");
+  try {
+    const view = await patchDraft({ language: lang });
+    state.view = view;
+    // Repaint everything that depends on language: the DE/EN form
+    // values in the resolved bag, the localized rule name in the
+    // header, and the fallback notice.
+    paintHeader();
+    paintLanguageRow();
+    paintLanguageFallback();
+    paintVariables();
+    paintPreview();
+    setSaveStatus(isEN() ? "Saved" : "Gespeichert");
+  } catch (err) {
+    if ((err as Error).name === "AbortError") return;
+    console.error("submission-draft language switch:", err);
+    setSaveStatus(isEN() ? "Save failed" : "Speichern fehlgeschlagen", true);
+    // Revert the radio to the persisted value so the UI doesn't lie
+    // about which language is active.
+    paintLanguageRow();
+  }
+}
+
+
 function paintVariables(): void {
   const host = document.getElementById("submission-draft-variables");
   if (!host || !state.view) return;

frontend/src/i18n-keys.ts

@@ -2620,6 +2620,10 @@ export type I18nKey =
   | "submissions.draft.action.new"
   | "submissions.draft.back"
   | "submissions.draft.import.button"
+  | "submissions.draft.language"
+  | "submissions.draft.language.de"
+  | "submissions.draft.language.en"
+  | "submissions.draft.language.fallback_notice"
   | "submissions.draft.loading"
   | "submissions.draft.name.placeholder"
   | "submissions.draft.notfound"

frontend/src/styles/global.css

@@ -5954,6 +5954,40 @@ dialog.modal::backdrop {
     color: var(--color-danger, #c00);
 }
 
+/* t-paliad-276 — DE/EN language toggle on the draft editor. Same look
+   as the rest of the sidebar mini-controls; muted label + inline radios
+   so it doesn't compete with the editor's primary inputs. */
+.submission-draft-language-row {
+    display: flex;
+    align-items: center;
+    gap: 0.75rem;
+    margin: 0.25rem 0 0.5rem 0;
+    font-size: 0.9em;
+}
+
+.submission-draft-language-label {
+    color: var(--color-text-muted);
+    text-transform: uppercase;
+    letter-spacing: 0.05em;
+    font-size: 0.85em;
+}
+
+.submission-draft-language-option {
+    display: inline-flex;
+    align-items: center;
+    gap: 0.25rem;
+    cursor: pointer;
+}
+
+.submission-draft-language-fallback {
+    font-size: 0.85em;
+    color: var(--color-text-muted);
+    margin: 0 0 0.5rem 0;
+    padding: 0.4rem 0.6rem;
+    border-left: 2px solid var(--color-warning, #d4a017);
+    background: var(--color-warning-bg, rgba(212, 160, 23, 0.08));
+}
+
 .submission-draft-variables {
     display: flex;
     flex-direction: column;

frontend/src/submission-draft.tsx

@@ -109,6 +109,47 @@ export function renderSubmissionDraft(): string {
                       </button>
                     </div>
 
+                    {/* t-paliad-276 — output language toggle (DE/EN).
+                        Hydrated by client/submission-draft.ts; switching
+                        autosaves the draft and re-renders the preview. */}
+                    <div
+                      className="submission-draft-language-row"
+                      id="submission-draft-language-row"
+                      role="radiogroup"
+                      aria-labelledby="submission-draft-language-label">
+                      <span
+                        id="submission-draft-language-label"
+                        className="submission-draft-language-label"
+                        data-i18n="submissions.draft.language">
+                        Sprache
+                      </span>
+                      <label className="submission-draft-language-option">
+                        <input
+                          type="radio"
+                          name="submission-draft-language"
+                          value="de"
+                          id="submission-draft-language-de"
+                        />
+                        <span data-i18n="submissions.draft.language.de">DE</span>
+                      </label>
+                      <label className="submission-draft-language-option">
+                        <input
+                          type="radio"
+                          name="submission-draft-language"
+                          value="en"
+                          id="submission-draft-language-en"
+                        />
+                        <span data-i18n="submissions.draft.language.en">EN</span>
+                      </label>
+                    </div>
+                    <p
+                      className="submission-draft-language-fallback"
+                      id="submission-draft-language-fallback"
+                      style="display:none"
+                      data-i18n="submissions.draft.language.fallback_notice">
+                      Fallback: universelles Skelett (keine sprachspezifische Vorlage).
+                    </p>
+
                     <p className="submission-draft-savestatus" id="submission-draft-savestatus" />
 
                     {/* t-paliad-277: "Aus Projekt importieren" + last-

internal/db/migrations/130_submission_drafts_language.down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE paliad.submission_drafts
+    DROP COLUMN IF EXISTS language;

internal/db/migrations/130_submission_drafts_language.up.sql

@@ -0,0 +1,17 @@
+-- t-paliad-276 / m/paliad#108: per-draft output language for the
+-- Submissions generator.
+--
+-- The submission editor lets the lawyer pick DE or EN per draft so the
+-- generator selects the matching template variant + resolves language-
+-- aware variables ({{procedural_event.name_de}} vs _en). Default is
+-- 'de' to match the primary-language convention in CLAUDE.md and to
+-- keep existing rows behaving exactly as before (every legacy draft
+-- was implicitly DE; the resolved bag for those drafts is unchanged
+-- under language='de').
+
+ALTER TABLE paliad.submission_drafts
+    ADD COLUMN IF NOT EXISTS language text NOT NULL DEFAULT 'de'
+    CONSTRAINT submission_drafts_language_check CHECK (language IN ('de', 'en'));
+
+COMMENT ON COLUMN paliad.submission_drafts.language IS
+    't-paliad-276: output language for the generated .docx. ''de'' or ''en''. Drives template variant selection ({code}.{lang}.docx fallback chain) and language-aware variable resolution.';

internal/handlers/files.go

@@ -97,6 +97,20 @@ var fileRegistry = map[string]fileEntry{
 		RepoName:     "mWorkRepo",
 		FilePath:     "6 - material/Templates/Word/Paliad/" + branding.Name + "/_firm-skeleton.docx",
 	},
+	// English skeleton variant (t-paliad-276). Sibling of
+	// `_skeleton.docx`; used when a draft's language='en' and no
+	// per-code EN template exists. If the file isn't authored yet in
+	// mWorkRepo, the Gitea fetch fails and resolveSubmissionTemplate
+	// falls through to the DE skeleton — visible to the user as the
+	// "Fallback: universelles Skelett" notice on the draft editor.
+	skeletonSubmissionENSlug: {
+		RawURL:       "https://mgit.msbls.de/m/mWorkRepo/raw/branch/main/6%20-%20material/Templates/Word/Paliad/" + branding.Name + "/_skeleton.en.docx",
+		DownloadName: branding.Name + " — Submission skeleton.docx",
+		ContentType:  "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+		RepoOwner:    "m",
+		RepoName:     "mWorkRepo",
+		FilePath:     "6 - material/Templates/Word/Paliad/" + branding.Name + "/_skeleton.en.docx",
+	},
 }
 
 // skeletonSubmissionSlug names the universal skeleton template inside
@@ -113,6 +127,11 @@ const skeletonSubmissionSlug = "submission/_skeleton.docx"
 // codes without a dedicated template still render with firm branding.
 const firmSkeletonSubmissionSlug = "submission/_firm-skeleton.docx"
 
+// skeletonSubmissionENSlug names the English skeleton variant used when
+// a draft's language='en' and no per-code EN template exists
+// (t-paliad-276). Same role as skeletonSubmissionSlug but in EN.
+const skeletonSubmissionENSlug = "submission/_skeleton.en.docx"
+
 // submissionTemplateRegistry maps a deadline-rule submission_code to a
 // fileRegistry slug. Lookup order matches the cronus design fallback
 // chain §8: per-firm `templates/{FIRM_NAME}/{code}.docx` first, then
@@ -122,14 +141,32 @@ const firmSkeletonSubmissionSlug = "submission/_firm-skeleton.docx"
 // the file itself lives in mWorkRepo and is served through the shared
 // Gitea proxy cache so refreshes are visible to all consumers in one
 // place.
+//
+// t-paliad-276: codes that ship an EN sibling
+// (e.g. `de.inf.lg.erwidg.en.docx`) also register it in
+// submissionTemplateENRegistry; the language-aware lookup
+// (resolveSubmissionTemplate(ctx, code, lang)) prefers the language-
+// suffixed slug and falls back to the unsuffixed one when no per-firm
+// EN variant exists.
 var submissionTemplateRegistry = map[string]string{
 	"de.inf.lg.erwidg": "submission/de.inf.lg.erwidg.docx",
 }
 
+// submissionTemplateENRegistry maps a submission_code to the EN
+// variant slug. Empty when no EN template has been authored — the
+// lookup falls through to the unsuffixed (DE-baked) template and the
+// editor surfaces the "Fallback: universelles Skelett" notice when
+// even the skeleton has no EN sibling.
+var submissionTemplateENRegistry = map[string]string{}
+
 // fetchSubmissionTemplateBytes returns the per-submission_code template
 // bytes (and provenance SHA) when one is registered. The bool result
 // distinguishes "no per-code template registered" (callers fall back to
 // HL Patents Style) from an upstream fetch error.
+//
+// Language-suffixed variants (t-paliad-276) are served via
+// fetchSubmissionTemplateBytesForLang — this base function returns the
+// unsuffixed registry entry only (the legacy DE-baked template).
 func fetchSubmissionTemplateBytes(ctx context.Context, submissionCode string) ([]byte, string, bool, error) {
 	slug, ok := submissionTemplateRegistry[submissionCode]
 	if !ok {
@@ -235,6 +272,113 @@ func handleFileRefresh(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, map[string]string{"ok": "true", "message": "Cache cleared"})
 }
 
+// fetchSubmissionTemplateBytesForLang returns the per-(code, lang)
+// template bytes when a language-suffixed variant is registered. Used
+// only for the EN variant today; DE goes through the unsuffixed
+// fetchSubmissionTemplateBytes (which is the legacy / authoritative
+// DE registry). t-paliad-276.
+//
+// Returned bool = "variant registered AND fetched OK". A registered
+// variant whose file 404s on Gitea returns (nil, "", false, nil) so
+// the caller falls through to the unsuffixed template, mirroring the
+// behaviour for unregistered codes.
+func fetchSubmissionTemplateBytesForLang(ctx context.Context, submissionCode, lang string) ([]byte, string, bool, error) {
+	if lang != "en" {
+		// Only EN has a separate registry today. DE goes through the
+		// unsuffixed path which is the authoritative DE template.
+		return nil, "", false, nil
+	}
+	slug, ok := submissionTemplateENRegistry[submissionCode]
+	if !ok {
+		return nil, "", false, nil
+	}
+	entry, ok := fileRegistry[slug]
+	if !ok {
+		return nil, "", false, fmt.Errorf("file proxy: submission template slug %q not registered", slug)
+	}
+	ce := getCacheEntry(slug)
+
+	ce.mu.RLock()
+	hasData := len(ce.data) > 0
+	needsCheck := time.Since(ce.lastChecked) >= checkInterval
+	ce.mu.RUnlock()
+
+	if !hasData {
+		if err := fileFetch(ce, entry); err != nil {
+			// Treat upstream miss as "variant unavailable" so the
+			// resolver falls through to the DE template instead of
+			// surfacing a 502.
+			log.Printf("file proxy: EN variant fetch failed for %s (%s): %v — falling through", submissionCode, slug, err)
+			return nil, "", false, nil
+		}
+	} else if needsCheck {
+		go fileCheckAndRefresh(ce, entry)
+	}
+
+	ce.mu.RLock()
+	defer ce.mu.RUnlock()
+	if len(ce.data) == 0 {
+		return nil, "", false, nil
+	}
+	out := make([]byte, len(ce.data))
+	copy(out, ce.data)
+	_ = ctx
+	return out, ce.sha, true, nil
+}
+
+// fetchSubmissionSkeletonBytesForLang returns the cached skeleton
+// template bytes for the requested language. EN falls back to DE when
+// the EN skeleton hasn't been authored yet (t-paliad-276). Returned
+// bool flags whether the bytes match the requested language — false
+// means the resolver should communicate "fallback" to the UI.
+func fetchSubmissionSkeletonBytesForLang(ctx context.Context, lang string) ([]byte, string, bool, error) {
+	if lang == "en" {
+		entry, ok := fileRegistry[skeletonSubmissionENSlug]
+		if ok {
+			ce := getCacheEntry(skeletonSubmissionENSlug)
+			ce.mu.RLock()
+			hasData := len(ce.data) > 0
+			needsCheck := time.Since(ce.lastChecked) >= checkInterval
+			ce.mu.RUnlock()
+			if !hasData {
+				if err := fileFetch(ce, entry); err == nil {
+					ce.mu.RLock()
+					if len(ce.data) > 0 {
+						out := make([]byte, len(ce.data))
+						copy(out, ce.data)
+						sha := ce.sha
+						ce.mu.RUnlock()
+						return out, sha, true, nil
+					}
+					ce.mu.RUnlock()
+				} else {
+					log.Printf("file proxy: EN skeleton fetch failed (%s): %v — falling back to DE", skeletonSubmissionENSlug, err)
+				}
+			} else {
+				if needsCheck {
+					go fileCheckAndRefresh(ce, entry)
+				}
+				ce.mu.RLock()
+				if len(ce.data) > 0 {
+					out := make([]byte, len(ce.data))
+					copy(out, ce.data)
+					sha := ce.sha
+					ce.mu.RUnlock()
+					return out, sha, true, nil
+				}
+				ce.mu.RUnlock()
+			}
+		}
+	}
+	// Fall through to the DE skeleton; bool=false flags that the
+	// returned bytes don't carry the requested language.
+	bytes, sha, err := fetchSubmissionSkeletonBytes(ctx)
+	if err != nil {
+		return nil, "", false, err
+	}
+	return bytes, sha, lang == "de", nil
+}
+
 // fetchSubmissionSkeletonBytes returns the cached universal skeleton
 // template bytes plus its provenance SHA. Sits between the per-firm
 // per-submission_code template (fetchSubmissionTemplateBytes) and the

internal/handlers/submission_drafts.go

@@ -68,6 +68,17 @@ type submissionDraftView struct {
 	Lang            string                  `json:"lang"`
 	HasTemplate     bool                    `json:"has_template"`
 	TemplateMissing bool                    `json:"template_missing,omitempty"`
+	// TemplateTier identifies which tier of resolveSubmissionTemplate
+	// produced the bytes — one of per_code_lang, per_code, skeleton_lang,
+	// skeleton, letterhead. Lets the editor distinguish a perfect
+	// per-firm match from a skeleton fallback. t-paliad-276.
+	TemplateTier string `json:"template_tier,omitempty"`
+	// LanguageFallback is true when the requested draft.language has no
+	// per-firm per-code template (e.g. EN draft falls back to the DE
+	// per-code template, or to the universal skeleton). UI surfaces a
+	// notice so the lawyer knows the rendered body lacks language-
+	// matched code-specific prose. t-paliad-276.
+	LanguageFallback bool `json:"language_fallback,omitempty"`
 	// AvailableParties is the project's full party roster (t-paliad-277)
 	// so the frontend can render the multi-select picker in one round-
 	// trip. Empty when the draft has no project attached.
@@ -89,6 +100,7 @@ type submissionDraftJSON struct {
 	SubmissionCode  string                  `json:"submission_code"`
 	UserID          uuid.UUID               `json:"user_id"`
 	Name            string                  `json:"name"`
+	Language        string                  `json:"language"`
 	Variables       services.PlaceholderMap `json:"variables"`
 	SelectedParties []uuid.UUID             `json:"selected_parties"`
 	LastExportedAt  *time.Time              `json:"last_exported_at,omitempty"`
@@ -119,6 +131,7 @@ type submissionDraftPatchInput struct {
 	Name            *string                  `json:"name,omitempty"`
 	Variables       *services.PlaceholderMap `json:"variables,omitempty"`
 	SelectedParties *[]uuid.UUID             `json:"selected_parties,omitempty"`
+	Language        *string                  `json:"language,omitempty"`
 }
 
 // ─────────────────────────────────────────────────────────────────────
@@ -353,7 +366,12 @@ func handlePatchSubmissionDraft(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	patch := services.DraftPatch{Name: input.Name, Variables: input.Variables, SelectedParties: input.SelectedParties}
+	patch := services.DraftPatch{
+		Name:            input.Name,
+		Variables:       input.Variables,
+		SelectedParties: input.SelectedParties,
+		Language:        input.Language,
+	}
 	d, err := dbSvc.submissionDraft.Update(r.Context(), uid, draftID, patch)
 	if err != nil {
 		writeSubmissionDraftServiceError(w, err)
@@ -434,7 +452,7 @@ func handlePreviewSubmissionDraft(w http.ResponseWriter, r *http.Request) {
 		writeSubmissionDraftServiceError(w, err)
 		return
 	}
-	tplBytes, _, err := resolveSubmissionTemplate(ctx, d.SubmissionCode)
+	tplBytes, _, _, err := resolveSubmissionTemplate(ctx, d.SubmissionCode, d.Language)
 	if err != nil {
 		log.Printf("submission_drafts: template fetch (draft=%s): %v", draftID, err)
 		writeJSON(w, http.StatusBadGateway, map[string]string{"error": "template upstream unreachable"})
@@ -483,7 +501,7 @@ func handleExportSubmissionDraft(w http.ResponseWriter, r *http.Request) {
 		writeSubmissionDraftServiceError(w, err)
 		return
 	}
-	tplBytes, tplSHA, err := resolveSubmissionTemplate(ctx, d.SubmissionCode)
+	tplBytes, tplSHA, _, err := resolveSubmissionTemplate(ctx, d.SubmissionCode, d.Language)
 	if err != nil {
 		log.Printf("submission_drafts: export template fetch (draft=%s): %v", draftID, err)
 		writeJSON(w, http.StatusBadGateway, map[string]string{"error": "template upstream unreachable"})
@@ -686,6 +704,7 @@ func handleGetGlobalSubmissionDraft(w http.ResponseWriter, r *http.Request) {
 type globalDraftPatchInput struct {
 	Name      *string                  `json:"name,omitempty"`
 	Variables *services.PlaceholderMap `json:"variables,omitempty"`
+	Language  *string                  `json:"language,omitempty"`
 	// projectIDProvided is true when the JSON included the "project_id"
 	// key (regardless of value); needed to distinguish "no change" from
 	// "set to null". Set by the custom UnmarshalJSON below.
@@ -700,6 +719,7 @@ func (g *globalDraftPatchInput) UnmarshalJSON(data []byte) error {
 	type alias struct {
 		Name            *string                  `json:"name,omitempty"`
 		Variables       *services.PlaceholderMap `json:"variables,omitempty"`
+		Language        *string                  `json:"language,omitempty"`
 		ProjectID       *uuid.UUID               `json:"project_id,omitempty"`
 		SelectedParties *[]uuid.UUID             `json:"selected_parties,omitempty"`
 	}
@@ -709,6 +729,7 @@ func (g *globalDraftPatchInput) UnmarshalJSON(data []byte) error {
 	}
 	g.Name = a.Name
 	g.Variables = a.Variables
+	g.Language = a.Language
 	g.ProjectID = a.ProjectID
 	g.SelectedParties = a.SelectedParties
 	// Detect whether "project_id" was present in the JSON object.
@@ -747,7 +768,12 @@ func handleGlobalPatchSubmissionDraft(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	patch := services.DraftPatch{Name: in.Name, Variables: in.Variables, SelectedParties: in.SelectedParties}
+	patch := services.DraftPatch{
+		Name:            in.Name,
+		Variables:       in.Variables,
+		SelectedParties: in.SelectedParties,
+		Language:        in.Language,
+	}
 	if in.projectIDProvided {
 		pid := in.ProjectID // may be nil → detach
 		patch.ProjectID = &pid
@@ -864,7 +890,7 @@ func handleGlobalExportSubmissionDraft(w http.ResponseWriter, r *http.Request) {
 		writeSubmissionDraftServiceError(w, err)
 		return
 	}
-	tplBytes, tplSHA, err := resolveSubmissionTemplate(ctx, d.SubmissionCode)
+	tplBytes, tplSHA, _, err := resolveSubmissionTemplate(ctx, d.SubmissionCode, d.Language)
 	if err != nil {
 		log.Printf("submission_drafts: export template fetch (draft=%s): %v", draftID, err)
 		writeJSON(w, http.StatusBadGateway, map[string]string{"error": "template upstream unreachable"})
@@ -963,7 +989,7 @@ func buildSubmissionDraftView(ctx context.Context, d *services.SubmissionDraft,
 		view.Rule.LegalSourcePretty = merged["rule.legal_source_pretty"]
 	}
 
-	tplBytes, _, err := resolveSubmissionTemplate(ctx, d.SubmissionCode)
+	tplBytes, _, tier, err := resolveSubmissionTemplate(ctx, d.SubmissionCode, d.Language)
 	if err != nil {
 		log.Printf("submission_drafts: template fetch for view (draft=%s): %v", d.ID, err)
 		view.TemplateMissing = true
@@ -971,6 +997,12 @@ func buildSubmissionDraftView(ctx context.Context, d *services.SubmissionDraft,
 		view.PreviewHTML = `<p class="preview-error">Vorlage konnte nicht geladen werden.</p>`
 		return view, nil
 	}
+	view.TemplateTier = string(tier)
+	// LanguageFallback signals "no per-firm template in the requested
+	// language" — the editor surfaces a notice so the lawyer knows the
+	// rendered body lacks code-specific prose. The per-code DE template
+	// counts as a fallback when the requested language is EN.
+	view.LanguageFallback = languageFallback(d.Language, tier)
 	html, err := dbSvc.submissionDraft.RenderPreview(ctx, d, tplBytes)
 	if err != nil {
 		return nil, err
@@ -979,52 +1011,101 @@ func buildSubmissionDraftView(ctx context.Context, d *services.SubmissionDraft,
 	return view, nil
 }
 
+// submissionTemplateTier enumerates which tier of the template
+// fallback chain produced the bytes returned by resolveSubmissionTemplate.
+// Used by the editor to surface "Fallback: universelles Skelett" when
+// the requested (code, lang) didn't have a dedicated template.
+type submissionTemplateTier string
+
+const (
+	tplTierPerCodeLang  submissionTemplateTier = "per_code_lang"  // {firm}/{code}.{lang}.docx
+	tplTierPerCode      submissionTemplateTier = "per_code"       // {firm}/{code}.docx (unsuffixed)
+	tplTierSkeletonLang submissionTemplateTier = "skeleton_lang"  // _skeleton.{lang}.docx
+	tplTierSkeleton     submissionTemplateTier = "skeleton"       // _skeleton.docx
+	tplTierLetterhead   submissionTemplateTier = "letterhead"     // HL Patents Style .dotm
+)
+
 // resolveSubmissionTemplate returns the .docx bytes for the given
-// submission code. Lookup order matches the cronus design fallback chain
-// §8 plus the t-paliad-259 universal-skeleton slot and the t-paliad-275
-// firm-skeleton slot:
+// (submission_code, language). Merges t-paliad-275 (firm-skeleton tier)
+// and t-paliad-276 (language-selector + EN skeleton tier). Lookup order:
 //
-//  1. per-firm per-submission_code template registered in
-//     submissionTemplateRegistry (e.g. de.inf.lg.erwidg.docx) — code-
-//     specific structure plus the full variable bag.
-//  2. firm-formatted _firm-skeleton.docx — full HL paragraph + character
-//     styles (HLpat-Heading-H1..H5, HLpat-Body-B0, HLpat-Header-Section,
-//     HLpat-Table-Recitals-*, HLpat-Signature, …) preserved from the
-//     source .dotm, the firm letterhead header/footer, plus the full
-//     48-key placeholder bag. Catches every code without a dedicated
-//     template so the editor still renders firm-branded output.
-//  3. universal _skeleton.docx — same variable bag, no firm formatting.
-//     Backstop for when the firm skeleton is unreachable (e.g. a future
-//     firm hasn't authored one yet).
-//  4. universal HL Patents Style .dotm — macro-only letterhead, no
-//     placeholders. Final fallback when even both skeletons are
-//     unreachable (mWorkRepo outage etc.). Preserves the
-//     pre-t-paliad-259 behaviour for resilience.
+//  1. per-firm per-(code, lang) template — most specific. e.g.
+//     `de.inf.lg.erwidg.en.docx` for EN drafts. t-paliad-276.
+//  2. per-firm per-code (unsuffixed) template — DE-baked baseline. The
+//     legacy registry shape from before the language selector landed.
+//  3. universal language-matched skeleton — `_skeleton.en.docx` for EN
+//     drafts. Skipped for DE drafts (steps 4+5 already cover DE).
+//  4. firm-formatted skeleton — `_firm-skeleton.docx` (t-paliad-275).
+//     HL paragraph + character styles + letterhead, full placeholder
+//     bag. DE-flavored: counts as language_fallback=true for EN drafts.
+//  5. universal _skeleton.docx — plain DE skeleton, no firm styles.
+//     Backstop when the firm skeleton is unreachable.
+//  6. universal HL Patents Style .dotm — macro-only letterhead, no
+//     placeholders. Last-ditch when every skeleton tier is unreachable.
 //
-// The returned SHA is the cache entry's commit SHA so the export audit
-// row can record provenance.
-func resolveSubmissionTemplate(ctx context.Context, submissionCode string) ([]byte, string, error) {
-	if data, sha, found, err := fetchSubmissionTemplateBytes(ctx, submissionCode); err != nil {
-		return nil, "", err
+// The returned SHA pins the audit row's template provenance. The tier
+// tells the editor whether the result language-matches the request so
+// it can surface a "Fallback: universelles Skelett" notice.
+func resolveSubmissionTemplate(ctx context.Context, submissionCode, lang string) ([]byte, string, submissionTemplateTier, error) {
+	if lang != "de" && lang != "en" {
+		lang = "de"
+	}
+	// 1. per-(code, lang)
+	if data, sha, found, err := fetchSubmissionTemplateBytesForLang(ctx, submissionCode, lang); err != nil {
+		return nil, "", "", err
 	} else if found {
-		return data, sha, nil
+		return data, sha, tplTierPerCodeLang, nil
 	}
+	// 2. per-code (unsuffixed)
+	if data, sha, found, err := fetchSubmissionTemplateBytes(ctx, submissionCode); err != nil {
+		return nil, "", "", err
+	} else if found {
+		return data, sha, tplTierPerCode, nil
+	}
+	// 3. language-matched skeleton — only meaningful for EN drafts; DE
+	//    drafts fall through to the firm/universal DE skeletons below.
+	if lang == "en" {
+		if data, sha, langMatched, err := fetchSubmissionSkeletonBytesForLang(ctx, lang); err == nil && langMatched {
+			return data, sha, tplTierSkeletonLang, nil
+		}
+	}
+	// 4. firm-formatted skeleton (HL styles, DE prose). For DE drafts
+	//    this is a first-class match; for EN drafts it counts as a
+	//    language fallback (handled by languageFallback()).
 	if data, sha, err := fetchFirmSkeletonBytes(ctx); err == nil {
-		return data, sha, nil
+		return data, sha, tplTierSkeleton, nil
 	} else {
-		log.Printf("submission_drafts: firm-skeleton fetch failed for code=%s, falling back to universal skeleton: %v", submissionCode, err)
+		log.Printf("submission_drafts: firm-skeleton fetch failed for code=%s lang=%s, falling back to universal skeleton: %v", submissionCode, lang, err)
 	}
+	// 5. universal plain DE skeleton.
 	if data, sha, err := fetchSubmissionSkeletonBytes(ctx); err == nil {
-		return data, sha, nil
+		return data, sha, tplTierSkeleton, nil
 	} else {
-		log.Printf("submission_drafts: skeleton fetch failed for code=%s, falling back to HL Patents Style: %v", submissionCode, err)
+		log.Printf("submission_drafts: skeleton fetch failed for code=%s lang=%s, falling back to HL Patents Style: %v", submissionCode, lang, err)
 	}
+	// 6. HL Patents Style letterhead (no placeholders, last-ditch).
 	bytes, err := fetchHLPatentsStyleBytes(ctx)
 	if err != nil {
-		return nil, "", err
+		return nil, "", "", err
 	}
 	sha := hlPatentsStyleSHA()
-	return bytes, sha, nil
+	return bytes, sha, tplTierLetterhead, nil
+}
+
+// languageFallback reports whether the resolved template tier failed
+// to match the requested draft language. For an EN draft, anything
+// other than per_code_lang or skeleton_lang is a fallback (per_code is
+// the legacy DE-baked template, skeleton is the DE skeleton). For a DE
+// draft, only `letterhead` counts as a fallback — the DE skeleton and
+// per-code template are both first-class DE outputs. t-paliad-276.
+func languageFallback(lang string, tier submissionTemplateTier) bool {
+	if tier == tplTierLetterhead {
+		return true
+	}
+	if strings.EqualFold(lang, "en") {
+		return tier != tplTierPerCodeLang && tier != tplTierSkeletonLang
+	}
+	return false
 }
 
 // hlPatentsStyleSHA reads the current cache SHA for the universal
@@ -1050,12 +1131,17 @@ func draftToJSON(d *services.SubmissionDraft) submissionDraftJSON {
 	if selected == nil {
 		selected = []uuid.UUID{}
 	}
+	lang := d.Language
+	if lang == "" {
+		lang = "de"
+	}
 	return submissionDraftJSON{
 		ID:              d.ID,
 		ProjectID:       d.ProjectID,
 		SubmissionCode:  d.SubmissionCode,
 		UserID:          d.UserID,
 		Name:            d.Name,
+		Language:        lang,
 		Variables:       vars,
 		SelectedParties: selected,
 		LastExportedAt:  d.LastExportedAt,

internal/handlers/submission_template_lang_test.go

@@ -0,0 +1,43 @@
+package handlers
+
+// Regression tests for the template-tier → language-fallback mapping
+// (t-paliad-276). The editor surfaces a "Fallback: universelles
+// Skelett" notice when the requested draft language has no per-firm
+// language-matched template — these tests pin which tier counts as a
+// fallback for each language so the UI signal stays stable.
+
+import "testing"
+
+func TestLanguageFallback(t *testing.T) {
+	t.Parallel()
+	cases := []struct {
+		name string
+		lang string
+		tier submissionTemplateTier
+		want bool
+	}{
+		// DE drafts: every non-letterhead tier is a first-class match.
+		{"de_per_code_lang", "de", tplTierPerCodeLang, false},
+		{"de_per_code", "de", tplTierPerCode, false},
+		{"de_skeleton_lang", "de", tplTierSkeletonLang, false},
+		{"de_skeleton", "de", tplTierSkeleton, false},
+		{"de_letterhead", "de", tplTierLetterhead, true},
+
+		// EN drafts: per_code (DE-baked) and skeleton (DE-baked) both
+		// surface the fallback notice so the lawyer knows the rendered
+		// body lacks EN prose.
+		{"en_per_code_lang", "en", tplTierPerCodeLang, false},
+		{"en_per_code", "en", tplTierPerCode, true},
+		{"en_skeleton_lang", "en", tplTierSkeletonLang, false},
+		{"en_skeleton", "en", tplTierSkeleton, true},
+		{"en_letterhead", "en", tplTierLetterhead, true},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			t.Parallel()
+			if got := languageFallback(c.lang, c.tier); got != c.want {
+				t.Errorf("languageFallback(%q, %q) = %v, want %v", c.lang, c.tier, got, c.want)
+			}
+		})
+	}
+}

internal/handlers/submissions.go

@@ -304,14 +304,23 @@ func handleGenerateProjectSubmission(w http.ResponseWriter, r *http.Request) {
 	ctx, cancel := context.WithTimeout(r.Context(), submissionRenderTimeout)
 	defer cancel()
 
-	tplBytes, _, err := resolveSubmissionTemplate(ctx, submissionCode)
+	// One-shot /generate has no draft row to pull `language` from —
+	// accept `?language=de|en` as an explicit override (t-paliad-276)
+	// and otherwise fall back to the user's UI language.
+	user, _ := dbSvc.users.GetByID(ctx, uid)
+	lang := strings.ToLower(strings.TrimSpace(r.URL.Query().Get("language")))
+	if lang != "de" && lang != "en" {
+		lang = userLang(user)
+	}
+
+	tplBytes, _, _, err := resolveSubmissionTemplate(ctx, submissionCode, lang)
 	if err != nil {
 		log.Printf("submissions: template fetch (project=%s code=%s): %v", projectID, submissionCode, err)
 		writeJSON(w, http.StatusBadGateway, map[string]string{"error": "template upstream unreachable"})
 		return
 	}
 
-	docx, resolved, err := dbSvc.submissionDraft.RenderProjectSubmission(ctx, uid, projectID, submissionCode, tplBytes)
+	docx, resolved, err := dbSvc.submissionDraft.RenderProjectSubmission(ctx, uid, projectID, submissionCode, lang, tplBytes)
 	if err != nil {
 		if errors.Is(err, services.ErrSubmissionRuleNotFound) {
 			writeJSON(w, http.StatusNotFound, map[string]string{

internal/services/submission_draft_language_test.go

@@ -0,0 +1,79 @@
+package services
+
+// Regression tests for the per-draft language column (t-paliad-276).
+// The draft's `language` value drives both the placeholder-bag
+// language pick (`procedural_event.name` → name_de vs name_en) and the
+// template-variant lookup (`{code}.{lang}.docx` fallback chain). These
+// tests pin the pure-function pieces — Build wiring needs DB fixtures
+// and lives in the handler-layer smoke path.
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/google/uuid"
+
+	"mgit.msbls.de/m/paliad/internal/models"
+)
+
+func TestNormalizeDraftLanguage(t *testing.T) {
+	t.Parallel()
+	cases := []struct {
+		in   string
+		want string
+	}{
+		{"de", "de"},
+		{"DE", "de"},
+		{" de ", "de"},
+		{"en", "en"},
+		{"EN", "en"},
+		{"  en  ", "en"},
+		{"fr", "de"},  // unknown collapses to de (the CHECK-allowed default)
+		{"", "de"},
+		{"english", "de"}, // strict — only the canonical two-letter code is accepted
+	}
+	for _, c := range cases {
+		if got := normalizeDraftLanguage(c.in); got != c.want {
+			t.Errorf("normalizeDraftLanguage(%q) = %q, want %q", c.in, got, c.want)
+		}
+	}
+}
+
+// The placeholder bag picks the language-matched value for the
+// canonical (procedural_event.name) and legacy (rule.name) keys based
+// on the lang argument. This pins the wiring used by Build when a
+// draft's language overrides the user's UI lang (t-paliad-276).
+func TestAddRuleVars_LanguageSelectsMatchedName(t *testing.T) {
+	t.Parallel()
+	code := "de.inf.lg.erwidg"
+	rule := &models.DeadlineRule{
+		ID:             uuid.New(),
+		SubmissionCode: &code,
+		Name:           "Klageerwiderung",
+		NameEN:         "Statement of Defence",
+	}
+	for _, lang := range []string{"de", "en"} {
+		bag := PlaceholderMap{}
+		addRuleVars(bag, rule, lang)
+		want := rule.Name
+		if strings.EqualFold(lang, "en") {
+			want = rule.NameEN
+		}
+		if got := bag["procedural_event.name"]; got != want {
+			t.Errorf("lang=%s: procedural_event.name = %q, want %q", lang, got, want)
+		}
+		if got := bag["rule.name"]; got != want {
+			t.Errorf("lang=%s: rule.name = %q, want %q (legacy alias must mirror canonical)", lang, got, want)
+		}
+		// The explicit *_de / *_en keys never change — both are always
+		// emitted so a template can pin one regardless of the draft's
+		// language. Regression guard against accidentally
+		// language-gating the explicit variants.
+		if bag["procedural_event.name_de"] != rule.Name {
+			t.Errorf("lang=%s: procedural_event.name_de = %q, want %q", lang, bag["procedural_event.name_de"], rule.Name)
+		}
+		if bag["procedural_event.name_en"] != rule.NameEN {
+			t.Errorf("lang=%s: procedural_event.name_en = %q, want %q", lang, bag["procedural_event.name_en"], rule.NameEN)
+		}
+	}
+}

internal/services/submission_draft_service.go

@@ -43,11 +43,16 @@ import (
 // parties / deadline state to resolve). All callers must check for nil
 // before treating it as a uuid.
 type SubmissionDraft struct {
-	ID                 uuid.UUID      `db:"id"                  json:"id"`
-	ProjectID          *uuid.UUID     `db:"project_id"          json:"project_id,omitempty"`
-	SubmissionCode     string         `db:"submission_code"     json:"submission_code"`
-	UserID             uuid.UUID      `db:"user_id"             json:"user_id"`
-	Name               string         `db:"name"                json:"name"`
+	ID             uuid.UUID  `db:"id"                  json:"id"`
+	ProjectID      *uuid.UUID `db:"project_id"          json:"project_id,omitempty"`
+	SubmissionCode string     `db:"submission_code"     json:"submission_code"`
+	UserID         uuid.UUID  `db:"user_id"             json:"user_id"`
+	Name           string     `db:"name"                json:"name"`
+	// Language is the output language for the generated .docx — 'de' or
+	// 'en'. Drives the template-variant lookup ({code}.{lang}.docx
+	// fallback chain) and language-aware variable resolution
+	// ({{procedural_event.name}} → name_de or name_en). t-paliad-276.
+	Language           string         `db:"language"            json:"language"`
 	VariablesRaw       []byte         `db:"variables"           json:"-"`
 	SelectedPartiesRaw pq.StringArray `db:"selected_parties"    json:"-"`
 	LastExportedAt     *time.Time     `db:"last_exported_at"    json:"last_exported_at,omitempty"`
@@ -108,6 +113,10 @@ type DraftPatch struct {
 	// the column; pass *p = nil or an empty slice to reset to "include
 	// every party on the project" (the backward-compat default).
 	SelectedParties *[]uuid.UUID
+
+	// Language sets the output language. Valid values: "de", "en".
+	// Anything else returns ErrInvalidInput. t-paliad-276.
+	Language *string
 }
 
 // ErrSubmissionDraftNotFound is the sentinel for "no draft with that id
@@ -120,7 +129,7 @@ var ErrSubmissionDraftNameTaken = errors.New("submission draft: name already tak
 
 // draftColumns is the canonical select list — kept in one place so
 // every fetch stays in sync.
-const draftColumns = `id, project_id, submission_code, user_id, name,
+const draftColumns = `id, project_id, submission_code, user_id, name, language,
                       variables, selected_parties,
                       last_exported_at, last_exported_sha,
                       last_imported_at,
@@ -173,7 +182,7 @@ type DraftWithProject struct {
 func (s *SubmissionDraftService) ListAllForUser(ctx context.Context, userID uuid.UUID) ([]DraftWithProject, error) {
 	var rows []DraftWithProject
 	err := s.db.SelectContext(ctx, &rows,
-		`SELECT d.id, d.project_id, d.submission_code, d.user_id, d.name,
+		`SELECT d.id, d.project_id, d.submission_code, d.user_id, d.name, d.language,
 		        d.variables, d.selected_parties,
 		        d.last_exported_at, d.last_exported_sha, d.last_imported_at,
 		        d.created_at, d.updated_at,
@@ -280,13 +289,18 @@ func (s *SubmissionDraftService) Create(ctx context.Context, userID uuid.UUID, p
 	if err != nil {
 		return nil, err
 	}
+	// Seed the new draft's output language from the user's UI lang so
+	// the editor opens in the language the lawyer is already working in.
+	// Anything other than "en" normalizes to "de" — matches the DB CHECK
+	// constraint and the project's primary-language default.
+	draftLang := normalizeDraftLanguage(lang)
 	var d SubmissionDraft
 	err = s.db.GetContext(ctx, &d,
 		`INSERT INTO paliad.submission_drafts
-		     (project_id, submission_code, user_id, name)
-		 VALUES ($1, $2, $3, $4)
+		     (project_id, submission_code, user_id, name, language)
+		 VALUES ($1, $2, $3, $4, $5)
 		 RETURNING `+draftColumns,
-		projectID, submissionCode, userID, name)
+		projectID, submissionCode, userID, name, draftLang)
 	if err != nil {
 		return nil, fmt.Errorf("create submission draft: %w", err)
 	}
@@ -422,6 +436,17 @@ func (s *SubmissionDraftService) Update(ctx context.Context, userID, draftID uui
 		idx++
 	}
 
+	if patch.Language != nil {
+		newLang := strings.ToLower(strings.TrimSpace(*patch.Language))
+		if newLang != "de" && newLang != "en" {
+			return nil, ErrInvalidInput
+		}
+		setParts = append(setParts, fmt.Sprintf("language = $%d", idx))
+		args = append(args, newLang)
+		idx++
+	}
+
+
 	if len(setParts) == 0 {
 		return existing, nil
 	}
@@ -581,6 +606,10 @@ func (s *SubmissionDraftService) BuildRenderBag(ctx context.Context, draft *Subm
 		ProjectID:       draft.ProjectID,
 		SubmissionCode:  draft.SubmissionCode,
 		SelectedParties: draft.SelectedParties,
+		// The draft's language overrides the user's UI lang — the lawyer
+		// can author an EN draft in a DE-UI session and vice versa
+		// (t-paliad-276). Empty / unknown falls back to "de".
+		Lang: normalizeDraftLanguage(draft.Language),
 	})
 	if err != nil {
 		return nil, nil, err
@@ -635,12 +664,13 @@ func (s *SubmissionDraftService) Export(ctx context.Context, draft *SubmissionDr
 // ProjectService.GetByID — callers get ErrNotFound on no-access.
 // ErrSubmissionRuleNotFound surfaces when no published rule matches the
 // requested submission_code.
-func (s *SubmissionDraftService) RenderProjectSubmission(ctx context.Context, userID, projectID uuid.UUID, submissionCode string, templateBytes []byte) ([]byte, *SubmissionVarsResult, error) {
+func (s *SubmissionDraftService) RenderProjectSubmission(ctx context.Context, userID, projectID uuid.UUID, submissionCode, lang string, templateBytes []byte) ([]byte, *SubmissionVarsResult, error) {
 	pid := projectID
 	resolved, err := s.vars.Build(ctx, SubmissionVarsContext{
 		UserID:         userID,
 		ProjectID:      &pid,
 		SubmissionCode: submissionCode,
+		Lang:           normalizeDraftLanguage(lang),
 	})
 	if err != nil {
 		return nil, nil, err
@@ -698,6 +728,19 @@ func (d *SubmissionDraft) decodeSelectedParties() error {
 	return nil
 }
 
+// normalizeDraftLanguage maps any input to one of the two allowed
+// language values for paliad.submission_drafts.language. Anything other
+// than "en" (case-insensitive) collapses to "de" — matches the DB CHECK
+// constraint, the project's primary-language default, and the seed
+// behaviour for existing rows that came in before the column existed.
+func normalizeDraftLanguage(lang string) string {
+	if strings.EqualFold(strings.TrimSpace(lang), "en") {
+		return "en"
+	}
+	return "de"
+}
+
+
 // Compile-time guard: ensure the *models.User reference in the import
 // graph doesn't get optimised away by linters. The service doesn't
 // dereference User directly — that happens in SubmissionVarsService —

internal/services/submission_vars.go

@@ -83,6 +83,13 @@ type SubmissionVarsContext struct {
 	ProjectID       *uuid.UUID
 	SubmissionCode  string
 	SelectedParties []uuid.UUID
+	// Lang pins the output language for this Build, overriding the
+	// caller's UI preference (user.Lang). When empty, Build falls back
+	// to user.Lang so existing callers (the format-only Slice 1 path)
+	// keep working unchanged. The draft editor passes the per-draft
+	// `language` column (t-paliad-276) so DE/EN can be picked
+	// independently of the UI session.
+	Lang string
 }
 
 // SubmissionVarsResult bundles the placeholder map with the lookup
@@ -132,7 +139,15 @@ func (s *SubmissionVarsService) Build(ctx context.Context, in SubmissionVarsCont
 		return nil, err
 	}
 
-	lang := user.Lang
+	// Per-call Lang override (t-paliad-276) wins over the user's UI
+	// language so the draft editor can render an EN .docx from a DE-UI
+	// session and vice versa. Falls back to the user pref when the
+	// caller didn't specify, preserving the format-only Slice 1
+	// behaviour.
+	lang := strings.ToLower(strings.TrimSpace(in.Lang))
+	if lang != "de" && lang != "en" {
+		lang = user.Lang
+	}
 	if lang == "" {
 		lang = "de"
 	}