fix: Restore all files lost during destructive rebase

A previous `git pull --rebase origin main` dropped 177 local commits,
losing 3400+ files across admin-v2, backend, studio-v2, website,
klausur-service, and many other services. The partial restore attempt
(660295e2) only recovered some files.

This commit restores all missing files from pre-rebase ref 98933f5e
while preserving post-rebase additions (night-scheduler, night-mode UI,
NightModeWidget dashboard integration).

Restored features include:
- AI Module Sidebar (FAB), OCR Labeling, OCR Compare
- GPU Dashboard, RAG Pipeline, Magic Help
- Klausur-Korrektur (8 files), Abitur-Archiv (5+ files)
- Companion, Zeugnisse-Crawler, Screen Flow
- Full backend, studio-v2, website, klausur-service
- All compliance SDKs, agent-core, voice-service
- CI/CD configs, documentation, scripts

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

consent-service/internal/middleware/request_id.go

@@ -0,0 +1,75 @@
+package middleware
+
+import (
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+)
+
+const (
+	// RequestIDHeader is the primary header for request IDs
+	RequestIDHeader = "X-Request-ID"
+	// CorrelationIDHeader is an alternative header for distributed tracing
+	CorrelationIDHeader = "X-Correlation-ID"
+	// RequestIDKey is the context key for storing the request ID
+	RequestIDKey = "request_id"
+)
+
+// RequestID returns a middleware that generates and propagates request IDs.
+//
+// For each incoming request:
+// 1. Check for existing X-Request-ID or X-Correlation-ID header
+// 2. If not present, generate a new UUID
+// 3. Store in Gin context for use by handlers and logging
+// 4. Add to response headers
+//
+// Usage:
+//
+//	r.Use(middleware.RequestID())
+//
+//	func handler(c *gin.Context) {
+//	    requestID := middleware.GetRequestID(c)
+//	    log.Printf("[%s] Processing request", requestID)
+//	}
+func RequestID() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		// Try to get existing request ID from headers
+		requestID := c.GetHeader(RequestIDHeader)
+		if requestID == "" {
+			requestID = c.GetHeader(CorrelationIDHeader)
+		}
+
+		// Generate new ID if not provided
+		if requestID == "" {
+			requestID = uuid.New().String()
+		}
+
+		// Store in context for handlers and logging
+		c.Set(RequestIDKey, requestID)
+
+		// Add to response headers
+		c.Header(RequestIDHeader, requestID)
+		c.Header(CorrelationIDHeader, requestID)
+
+		c.Next()
+	}
+}
+
+// GetRequestID retrieves the request ID from the Gin context.
+// Returns empty string if no request ID is set.
+//
+// Usage:
+//
+//	requestID := middleware.GetRequestID(c)
+func GetRequestID(c *gin.Context) string {
+	if id, exists := c.Get(RequestIDKey); exists {
+		if idStr, ok := id.(string); ok {
+			return idStr
+		}
+	}
+	return ""
+}
+
+// RequestIDFromContext is an alias for GetRequestID for API compatibility.
+func RequestIDFromContext(c *gin.Context) string {
+	return GetRequestID(c)
+}