Let the same choice open notes and drafts

The picker in the bell now governs both lists, so note_subscriptions is
renamed to colleague_subscriptions -- a name that only mentions notes would
mislead the next reader.

Reading and writing a draft now reach differently far. hire_drafts_owner
(for all) is split into four policies: select lets in your own drafts and
those of the people you added, while insert/update/delete stay with the
owner. A draft is unfinished work with no lock and no history; two people
writing into the same row would overwrite each other silently.

That split forces a change in the actions: a policy does not reject a write,
it lets it hit no rows. saveHireDraft and deleteHireDraft now read the row
count instead of reporting success over a row that never changed.

The card shows a foreign draft with its author and without Fortsetzen or
Loeschen -- offering a button that reliably ends in a database error is a
promise without cover.

check-schema-types.mjs learns `alter table ... rename to`; without it the
drift check reports one rename as two errors.

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

tests/unit/notes-visibility.test.ts

@@ -48,7 +48,7 @@ describe("sichtbareNotizen", () => {
     const s = sql();
     expect(s).toContain("exists");
     expect(s).not.toContain("not exists");
-    expect(s).toContain("from note_subscriptions s");
+    expect(s).toContain("from colleague_subscriptions s");
     expect(s).toContain("s.user_id = $");
     expect(s).toContain("s.author_user_id = \"n\".\"author_user_id\"");
   });