feat: UPC deadline determination — event-driven model with proceeding timeline

Full event-driven deadline determination system ported from youpc.org:

Backend:
- DetermineService: walks proceeding event tree, calculates cascading
  dates with holiday adjustment and conditional logic
- GET /api/proceeding-types/{code}/timeline — full event tree structure
- POST /api/deadlines/determine — calculate timeline with conditions
- POST /api/cases/{caseID}/deadlines/batch — batch-create deadlines
- DeadlineRule model: added is_spawn, spawn_label fields
- GetFullTimeline: recursive CTE following cross-type spawn branches
- Conditional deadlines: condition_rule_id toggles alt_duration/rule_code
  (e.g. Reply changes from RoP.029b to RoP.029a when CCR is filed)
- Seed SQL with full UPC event trees (INF, REV, CCR, APM, APP, AMD)

Frontend:
- DeadlineWizard: interactive proceeding timeline with step-by-step flow
  1. Select proceeding type (visual cards)
  2. Enter trigger event date
  3. Toggle conditional branches (CCR, Appeal, Amend)
  4. See full calculated timeline with color-coded urgency
  5. Batch-create all deadlines on a selected case
- Visual timeline tree with party icons, rule codes, duration badges
- Kept existing DeadlineCalculator as "Schnell" quick mode

Also resolved merge conflicts across 6 files (auth, router, handlers)
merging role-based permissions + audit trail features.

backend/internal/services/deadline_rule_service.go

@@ -8,6 +8,12 @@ import (
 	"mgit.msbls.de/m/KanzlAI-mGMT/internal/models"
 )
 
+const ruleColumns = `id, proceeding_type_id, parent_id, code, name, description,
+	primary_party, event_type, is_mandatory, duration_value, duration_unit,
+	timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
+	alt_duration_value, alt_duration_unit, alt_rule_code,
+	is_spawn, spawn_label, is_active, created_at, updated_at`
+
 // DeadlineRuleService handles deadline rule queries
 type DeadlineRuleService struct {
 	db *sqlx.DB
@@ -25,21 +31,13 @@ func (s *DeadlineRuleService) List(proceedingTypeID *int) ([]models.DeadlineRule
 
 	if proceedingTypeID != nil {
 		err = s.db.Select(&rules,
-			`SELECT id, proceeding_type_id, parent_id, code, name, description,
-			        primary_party, event_type, is_mandatory, duration_value, duration_unit,
-			        timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
-			        alt_duration_value, alt_duration_unit, alt_rule_code, is_active,
-			        created_at, updated_at
+			`SELECT `+ruleColumns+`
 			 FROM deadline_rules
 			 WHERE proceeding_type_id = $1 AND is_active = true
 			 ORDER BY sequence_order`, *proceedingTypeID)
 	} else {
 		err = s.db.Select(&rules,
-			`SELECT id, proceeding_type_id, parent_id, code, name, description,
-			        primary_party, event_type, is_mandatory, duration_value, duration_unit,
-			        timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
-			        alt_duration_value, alt_duration_unit, alt_rule_code, is_active,
-			        created_at, updated_at
+			`SELECT `+ruleColumns+`
 			 FROM deadline_rules
 			 WHERE is_active = true
 			 ORDER BY proceeding_type_id, sequence_order`)
@@ -72,11 +70,7 @@ func (s *DeadlineRuleService) GetRuleTree(proceedingTypeCode string) ([]RuleTree
 	// Get all rules for this proceeding type
 	var rules []models.DeadlineRule
 	err = s.db.Select(&rules,
-		`SELECT id, proceeding_type_id, parent_id, code, name, description,
-		        primary_party, event_type, is_mandatory, duration_value, duration_unit,
-		        timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
-		        alt_duration_value, alt_duration_unit, alt_rule_code, is_active,
-		        created_at, updated_at
+		`SELECT `+ruleColumns+`
 		 FROM deadline_rules
 		 WHERE proceeding_type_id = $1 AND is_active = true
 		 ORDER BY sequence_order`, pt.ID)
@@ -87,6 +81,36 @@ func (s *DeadlineRuleService) GetRuleTree(proceedingTypeCode string) ([]RuleTree
 	return buildTree(rules), nil
 }
 
+// GetFullTimeline returns the full event tree for a proceeding type using a recursive CTE.
+// Unlike GetRuleTree, this follows parent_id across proceeding types (includes cross-type spawns).
+func (s *DeadlineRuleService) GetFullTimeline(proceedingTypeCode string) ([]models.DeadlineRule, *models.ProceedingType, error) {
+	var pt models.ProceedingType
+	err := s.db.Get(&pt,
+		`SELECT id, code, name, description, jurisdiction, default_color, sort_order, is_active
+		 FROM proceeding_types
+		 WHERE code = $1 AND is_active = true`, proceedingTypeCode)
+	if err != nil {
+		return nil, nil, fmt.Errorf("resolving proceeding type %q: %w", proceedingTypeCode, err)
+	}
+
+	var rules []models.DeadlineRule
+	err = s.db.Select(&rules, `
+		WITH RECURSIVE tree AS (
+			SELECT * FROM deadline_rules
+			WHERE proceeding_type_id = $1 AND parent_id IS NULL AND is_active = true
+			UNION ALL
+			SELECT dr.* FROM deadline_rules dr
+			JOIN tree t ON dr.parent_id = t.id
+			WHERE dr.is_active = true
+		)
+		SELECT `+ruleColumns+` FROM tree ORDER BY sequence_order`, pt.ID)
+	if err != nil {
+		return nil, nil, fmt.Errorf("fetching timeline for type %q: %w", proceedingTypeCode, err)
+	}
+
+	return rules, &pt, nil
+}
+
 // GetByIDs returns deadline rules by their IDs
 func (s *DeadlineRuleService) GetByIDs(ids []string) ([]models.DeadlineRule, error) {
 	if len(ids) == 0 {
@@ -94,11 +118,7 @@ func (s *DeadlineRuleService) GetByIDs(ids []string) ([]models.DeadlineRule, err
 	}
 
 	query, args, err := sqlx.In(
-		`SELECT id, proceeding_type_id, parent_id, code, name, description,
-		        primary_party, event_type, is_mandatory, duration_value, duration_unit,
-		        timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
-		        alt_duration_value, alt_duration_unit, alt_rule_code, is_active,
-		        created_at, updated_at
+		`SELECT `+ruleColumns+`
 		 FROM deadline_rules
 		 WHERE id IN (?) AND is_active = true
 		 ORDER BY sequence_order`, ids)
@@ -119,11 +139,7 @@ func (s *DeadlineRuleService) GetByIDs(ids []string) ([]models.DeadlineRule, err
 func (s *DeadlineRuleService) GetRulesForProceedingType(proceedingTypeID int) ([]models.DeadlineRule, error) {
 	var rules []models.DeadlineRule
 	err := s.db.Select(&rules,
-		`SELECT id, proceeding_type_id, parent_id, code, name, description,
-		        primary_party, event_type, is_mandatory, duration_value, duration_unit,
-		        timing, rule_code, deadline_notes, sequence_order, condition_rule_id,
-		        alt_duration_value, alt_duration_unit, alt_rule_code, is_active,
-		        created_at, updated_at
+		`SELECT `+ruleColumns+`
 		 FROM deadline_rules
 		 WHERE proceeding_type_id = $1 AND is_active = true
 		 ORDER BY sequence_order`, proceedingTypeID)