Add repair notes journal with running feed, visibility, and status tagging

New repair_note table for timestamped journal entries on tickets. Each
note captures author, content, visibility (internal or customer-facing),
and the ticket status at time of writing. Notes display as a running
feed on the ticket detail page with newest first. Internal notes have
a lock icon, customer-visible notes highlighted in blue. Supports add
and delete with appropriate permission gating.

packages/backend/src/db/schema/repairs.ts

@@ -140,6 +140,26 @@ export const repairLineItems = pgTable('repair_line_item', {
   createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
 })
 
+export const repairNoteVisibilityEnum = pgEnum('repair_note_visibility', ['internal', 'customer'])
+
+export const repairNotes = pgTable('repair_note', {
+  id: uuid('id').primaryKey().defaultRandom(),
+  repairTicketId: uuid('repair_ticket_id')
+    .notNull()
+    .references(() => repairTickets.id),
+  authorId: uuid('author_id')
+    .notNull()
+    .references(() => users.id),
+  authorName: varchar('author_name', { length: 255 }).notNull(),
+  content: text('content').notNull(),
+  visibility: repairNoteVisibilityEnum('visibility').notNull().default('internal'),
+  ticketStatus: repairTicketStatusEnum('ticket_status'),
+  createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
+})
+
+export type RepairNote = typeof repairNotes.$inferSelect
+export type RepairNoteInsert = typeof repairNotes.$inferInsert
+
 export const repairServiceTemplates = pgTable('repair_service_template', {
   id: uuid('id').primaryKey().defaultRandom(),
   companyId: uuid('company_id')