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>

src/schemas/projects.schema.ts

@@ -27,6 +27,14 @@ export const CreateProjectNoteSchema = z.object({
   content: z.string().nullish(),
 });
 
+export const UpdateProjectNoteSchema = z.strictObject({
+  content: z
+    .string()
+    .trim()
+    .min(1, "Poznámka nesmí být prázdná")
+    .max(5000, "Poznámka může mít maximálně 5000 znaků"),
+});
+
 export type CreateProjectInput = z.infer<typeof CreateProjectSchema>;
 export type UpdateProjectInput = z.infer<typeof UpdateProjectSchema>;
 export type CreateProjectNoteInput = z.infer<typeof CreateProjectNoteSchema>;