Merge: S4 infra — gotenberg sidecar + poppler-utils (truthful base-preview render)

Dockerfile

@@ -11,7 +11,10 @@ COPY . .
 RUN CGO_ENABLED=0 go build -ldflags="-s -w" -o /paliad ./cmd/server
 
 FROM alpine:3.21
-RUN apk add --no-cache ca-certificates openssh-client
+# poppler-utils provides pdftoppm — used by the truthful base-preview render
+# (PDF→PNG per page) in the S4 preview pipeline (t-paliad-370). If absent, the
+# preview gracefully falls back to the structural HTML render.
+RUN apk add --no-cache ca-certificates openssh-client poppler-utils
 WORKDIR /app
 COPY --from=backend /paliad /app/paliad
 COPY --from=frontend /app/frontend/dist /app/dist

docker-compose.yml

@@ -47,9 +47,32 @@ services:
       # restarts. Unset → /admin/backups returns 503 (BackupService gate).
       - PALIAD_EXPORT_DIR=${PALIAD_EXPORT_DIR:-/var/lib/paliad/exports}
       # - ANTHROPIC_API_KEY=${ANTHROPIC_API_KEY}  # Phase H (AI Frist-Extraktion), currently deferred
+      # Truthful base-preview render (t-paliad-370 S4). GOTENBERG_URL points at
+      # the gotenberg sidecar below (LibreOffice-as-HTTP, .docx→PDF). Unset →
+      # preview gracefully falls back to structural HTML. PREVIEW_DPI optional.
+      - GOTENBERG_URL=${GOTENBERG_URL:-http://gotenberg:3000}
+      - PREVIEW_DPI=${PREVIEW_DPI:-110}
     volumes:
       - paliad_exports:/var/lib/paliad/exports
     restart: unless-stopped
+    depends_on:
+      - gotenberg
+
+  # LibreOffice-as-a-service sidecar for the truthful base-preview render
+  # (t-paliad-370 S4). Converts the export .docx → PDF over HTTP; paliad then
+  # rasterises PDF→PNG via poppler. Internal only (not exposed publicly).
+  # NOTE (fonts): stock gotenberg ships Liberation fonts (metric-compatible
+  # with Arial/Times) → preview layout is accurate, glyphs ~99% but not pixel-
+  # identical to the firm's Arial. A custom image baking the firm's licensed
+  # fonts is the pixel-perfect upgrade (t-paliad-371, m's call).
+  gotenberg:
+    image: gotenberg/gotenberg:8
+    restart: unless-stopped
+    expose:
+      - "3000"
+    command:
+      - gotenberg
+      - --api-timeout=30s
 
 volumes:
   paliad_exports: