feat: add admin screens, permissions and navigation

Seven admin controllers in a "Studia BM" navigation group, guarded by
jz.bm.access_courses, jz.bm.access_schedule and jz.bm.access_materials,
with Polish and English labels. Date and time fields are checked by the
models before a save and answered as 422 on the field.

controllers/deadlines.go

@@ -0,0 +1,38 @@
+// Code generated by summer make. DO NOT EDIT.
+
+package controllers
+
+import (
+	"git.golem15.com/golem15/summercms/modules/cabana"
+	"git.golem15.com/golem15/summercms/modules/pact"
+	"git.golem15.com/jakub/sm-bm-plugin/models"
+)
+
+var (
+	_ pact.AdminController   = deadlinesAdmin{}
+	_ pact.AdminRecordSource = deadlinesAdmin{}
+	_ pact.AdminPermissioned = deadlinesAdmin{}
+)
+
+// deadlinesAdmin is the admin controller for deadlines (terminarz).
+type deadlinesAdmin struct{ temporalHooks }
+
+func (deadlinesAdmin) ID() string        { return "jz.bm.deadlines" }
+func (deadlinesAdmin) ModelName() string { return "Deadline" }
+func (deadlinesAdmin) ConfigDir() string { return "controllers/deadlines" }
+
+// NewRecord returns the model the generic admin handlers query and fill.
+func (deadlinesAdmin) NewRecord() any { return &models.Deadline{} }
+
+// RequiredPermissions is checked before any schema or record is served.
+func (deadlinesAdmin) RequiredPermissions() []string {
+	return []string{PermSchedule}
+}
+
+// AdminFieldRelations binds the course picker.
+func (deadlinesAdmin) AdminFieldRelations() []cabana.FieldRelationContract {
+	return []cabana.FieldRelationContract{courseRelation("course_id")}
+}
+
+// DeadlinesController returns the jz.bm.deadlines admin controller.
+func DeadlinesController() pact.AdminController { return deadlinesAdmin{} }