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>

school-service/internal/handlers/handlers.go

@@ -0,0 +1,66 @@
+package handlers
+
+import (
+	"net/http"
+
+	"github.com/breakpilot/school-service/internal/services"
+	"github.com/gin-gonic/gin"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// Handler holds all the service dependencies
+type Handler struct {
+	classService       *services.ClassService
+	examService        *services.ExamService
+	gradeService       *services.GradeService
+	gradebookService   *services.GradebookService
+	certificateService *services.CertificateService
+	aiService          *services.AIService
+}
+
+// NewHandler creates a new Handler with all services
+func NewHandler(db *pgxpool.Pool, llmGatewayURL string) *Handler {
+	classService := services.NewClassService(db)
+	examService := services.NewExamService(db)
+	gradeService := services.NewGradeService(db)
+	gradebookService := services.NewGradebookService(db)
+	certificateService := services.NewCertificateService(db, gradeService, gradebookService)
+	aiService := services.NewAIService(llmGatewayURL)
+
+	return &Handler{
+		classService:       classService,
+		examService:        examService,
+		gradeService:       gradeService,
+		gradebookService:   gradebookService,
+		certificateService: certificateService,
+		aiService:          aiService,
+	}
+}
+
+// Health returns the service health status
+func (h *Handler) Health(c *gin.Context) {
+	c.JSON(http.StatusOK, gin.H{
+		"status":  "healthy",
+		"service": "school-service",
+	})
+}
+
+// getUserID extracts the user ID from the context (set by auth middleware)
+func getUserID(c *gin.Context) string {
+	return c.GetString("user_id")
+}
+
+// respondError sends an error response
+func respondError(c *gin.Context, status int, message string) {
+	c.JSON(status, gin.H{"error": message})
+}
+
+// respondSuccess sends a success response with data
+func respondSuccess(c *gin.Context, data interface{}) {
+	c.JSON(http.StatusOK, data)
+}
+
+// respondCreated sends a created response with data
+func respondCreated(c *gin.Context, data interface{}) {
+	c.JSON(http.StatusCreated, data)
+}