feat: Tender-Analyse Pipeline — Upload, Extraction, Control-Matching

Phase 3 des Payment Compliance Moduls:
1. Backend: Tender Upload + LLM Requirement Extraction + Control Matching
   - DB Migration 025 (tender_analyses Tabelle)
   - TenderHandlers: Upload, Extract, Match, List, Get (5 Endpoints)
   - LLM-Extraktion via Anthropic API mit Keyword-Fallback
   - Control-Matching mit Domain-Bonus + Keyword-Overlap Relevance
2. Frontend: Dritter Tab "Ausschreibung" in /sdk/payment-compliance
   - PDF/TXT/Word Upload mit Drag-Area
   - Automatische Analyse-Pipeline (Upload → Extract → Match)
   - Ergebnis-Dashboard: Abgedeckt/Teilweise/Luecken
   - Requirement-by-Requirement Matching mit Control-IDs + Relevanz%
   - Gap-Beschreibung fuer nicht-gematchte Requirements
   - Analyse-Historie mit Klick-to-Detail

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ai-compliance-sdk/internal/api/handlers/payment_handlers.go

@@ -95,6 +95,11 @@ func loadControlLibrary() *PaymentControlLibrary {
 	return &PaymentControlLibrary{}
 }
 
+// GetControlLibrary returns the loaded control library (for tender matching)
+func (h *PaymentHandlers) GetControlLibrary() *PaymentControlLibrary {
+	return h.controls
+}
+
 // ListControls returns the control library
 func (h *PaymentHandlers) ListControls(c *gin.Context) {
 	domain := c.Query("domain")