Add timetable scheduler Phases 1 + 2 to school-service

Phase 1 — Stammdaten (7 tables):
  tt_class, tt_period, tt_room, tt_subject, tt_teacher,
  tt_curriculum, tt_assignment with CRUD endpoints.

Phase 2 — Constraints (15 typed tables):
  Teacher (6): unavailable_day, unavailable_window, max_hours_day,
    max_hours_week, excluded_subject, excluded_room
  Subject (5): min_day_gap, max_consecutive, contiguous_when_repeated,
    preferred_period, double_lesson
  Class (2): max_hours_day, no_gaps
  Room (2): requires_type, unavailable

Each constraint row carries is_hard / weight / active / note /
created_by_user_id; ownership enforced via WHERE EXISTS against the
parent tt_teacher/tt_class/tt_subject/tt_room row.

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

school-service/internal/handlers/timetable_relation_handlers.go

@@ -0,0 +1,104 @@
+package handlers
+
+import (
+	"net/http"
+
+	"github.com/breakpilot/school-service/internal/models"
+	"github.com/gin-gonic/gin"
+)
+
+// ---------- Curriculum ----------
+
+func (h *Handler) CreateTimetableCurriculum(c *gin.Context) {
+	uid := getUserID(c)
+	if uid == "" {
+		respondError(c, http.StatusUnauthorized, "User not authenticated")
+		return
+	}
+	var req models.CreateTimetableCurriculumRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		respondError(c, http.StatusBadRequest, "Invalid request: "+err.Error())
+		return
+	}
+	out, err := h.timetableService.CreateCurriculum(c.Request.Context(), uid, &req)
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "Failed to create curriculum: "+err.Error())
+		return
+	}
+	respondCreated(c, out)
+}
+
+func (h *Handler) ListTimetableCurriculum(c *gin.Context) {
+	uid := getUserID(c)
+	if uid == "" {
+		respondError(c, http.StatusUnauthorized, "User not authenticated")
+		return
+	}
+	out, err := h.timetableService.ListCurriculum(c.Request.Context(), uid)
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "Failed to list curriculum: "+err.Error())
+		return
+	}
+	respondSuccess(c, out)
+}
+
+func (h *Handler) DeleteTimetableCurriculum(c *gin.Context) {
+	uid := getUserID(c)
+	if uid == "" {
+		respondError(c, http.StatusUnauthorized, "User not authenticated")
+		return
+	}
+	if err := h.timetableService.DeleteCurriculum(c.Request.Context(), c.Param("id"), uid); err != nil {
+		respondError(c, http.StatusInternalServerError, "Failed to delete curriculum: "+err.Error())
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"message": "Curriculum entry deleted"})
+}
+
+// ---------- Assignment ----------
+
+func (h *Handler) CreateTimetableAssignment(c *gin.Context) {
+	uid := getUserID(c)
+	if uid == "" {
+		respondError(c, http.StatusUnauthorized, "User not authenticated")
+		return
+	}
+	var req models.CreateTimetableAssignmentRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		respondError(c, http.StatusBadRequest, "Invalid request: "+err.Error())
+		return
+	}
+	out, err := h.timetableService.CreateAssignment(c.Request.Context(), uid, &req)
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "Failed to create assignment: "+err.Error())
+		return
+	}
+	respondCreated(c, out)
+}
+
+func (h *Handler) ListTimetableAssignments(c *gin.Context) {
+	uid := getUserID(c)
+	if uid == "" {
+		respondError(c, http.StatusUnauthorized, "User not authenticated")
+		return
+	}
+	out, err := h.timetableService.ListAssignments(c.Request.Context(), uid)
+	if err != nil {
+		respondError(c, http.StatusInternalServerError, "Failed to list assignments: "+err.Error())
+		return
+	}
+	respondSuccess(c, out)
+}
+
+func (h *Handler) DeleteTimetableAssignment(c *gin.Context) {
+	uid := getUserID(c)
+	if uid == "" {
+		respondError(c, http.StatusUnauthorized, "User not authenticated")
+		return
+	}
+	if err := h.timetableService.DeleteAssignment(c.Request.Context(), c.Param("id"), uid); err != nil {
+		respondError(c, http.StatusInternalServerError, "Failed to delete assignment: "+err.Error())
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"message": "Assignment deleted"})
+}