feat(iace): Klaerungen Phase 2 — Sidebar-Counter + CSV-Export + Hazard-Banner

Three pieces complete the Klaerungen UX:

1. Sidebar-Counter: layout.tsx polls /clarifications and shows a
   colored open-count badge on the "Klaerungen" nav item. Refreshes
   whenever the user changes route.

2. CSV-Export: new backend endpoint
   GET /sdk/v1/iace/projects/:id/clarifications.csv produces a UTF-8-
   BOM-prefixed semicolon-separated CSV (Excel-friendly) with ID,
   Quelle, Kategorie, Frage, Status, Antwort, Begruendung, Bearbeiter,
   answered_at, anzahl Gefaehrdungen, Gefaehrdungs-Namen, Norm-Refs.
   Frontend Klaerungen-Seite bekommt einen "CSV-Export"-Button.

3. Hazard-Banner statt Fragentext im Benchmark-Detail: the previous
   bulleted clarification list was duplicated across 48 hazards for a
   single FANUC question. Phase 2 replaces it with a compact status
   badge — "N offene Klaerung(en) — Klaerungen-Seite oeffnen" (orange)
   or "Alle N Klaerungen beantwortet" (green) with a direct link.

Backend cleanup: iace_handler_init.go no longer appends the "Mit
Anlagenbauer zu klaeren" block to Hazard.Description. The description
stays focused on the scenario; clarifications live in the dedicated
endpoint and answers persist across re-inits via project.metadata.
The aggregated "Referenzierte Normen" line on the hazard is kept.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ai-compliance-sdk/internal/app/routes.go

@@ -454,6 +454,7 @@ func registerIACERoutes(v1 *gin.RouterGroup, h *handlers.IACEHandler) {
 
 		// Clarifications — aggregated open questions per project
 		iaceRoutes.GET("/projects/:id/clarifications", h.ListClarifications)
+		iaceRoutes.GET("/projects/:id/clarifications.csv", h.ExportClarificationsCSV)
 		iaceRoutes.POST("/projects/:id/clarifications/:cid/answer", h.AnswerClarification)
 	}
 }