feat(projects): editable notes with edit stamp + NoteCard bubble component

- author-only note editing (PUT /projects/:id/notes/:noteId, strict schema,
  audit with old/new content); edits stamped via new edited_at column
  (migration 20260612160000) and shown as '· upraveno <datum>'
- note deletion tightened to admin-only server-side (was any projects.edit
  holder via direct API)
- new NoteCard component: chat-bubble note row (initials avatar, wrapping
  header, inline editor, actions in the bubble corner so they don't squeeze
  content on mobile), table-matching edit/delete icons
- Odin project detail carries the edited_at stamp; route-level tests cover
  author-edit, foreign-edit 403, validation, admin-only delete

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

prisma/migrations/20260612160000_project_notes_edited_at/migration.sql

@@ -0,0 +1,3 @@
+-- AlterTable
+ALTER TABLE `project_notes` ADD COLUMN `edited_at` DATETIME(0) NULL;
+

prisma/schema.prisma

@@ -457,6 +457,7 @@ model project_notes {
   user_name  String?   @db.VarChar(100)
   content    String?   @db.Text
   created_at DateTime? @default(now()) @db.DateTime(0)
+  edited_at  DateTime? @db.DateTime(0)
   projects   projects  @relation(fields: [project_id], references: [id], onDelete: Cascade, onUpdate: NoAction, map: "project_notes_ibfk_1")
 
   @@index([project_id], map: "project_id")