## Implementation Plan: `@note` Tag Feature

**Approach:** Filter tab on existing saved page (Option B). The user sees a "Notes" tab alongside "All" on `/bookmarks/saved`. No separate `/notes` router. Keep UI changes minimal.

### Steps

1. **Database: add `source` column to `bookmarks` table**  
   - File: `devplacepy/database/schema.py`  
   - Add `create_column_by_example` call for `source` column with default `'manual'`.  
   - The existing index `idx_bookmarks_source` will then succeed.  
   - Ensure function `init_db()` calls this.

2. **Update `set_bookmark()` to accept `source` parameter**  
   - File: `devplacepy/content.py`, function `set_bookmark()` (line ~433)  
   - Add `source: str = "manual"` parameter.  
   - In the insert/update DB call, explicitly set `source` value.  
   - Update all existing call sites (there are 2: routes for manual bookmark toggle) to pass `source="manual"`.

3. **Add note detection in content creation chokepoints**  
   - File: `devplacepy/content.py`  
   - In `create_content_item()` (after line 196, before returning):  
     ```python
     if has_note(content_text):
         set_bookmark(request, user, target_type, uid, saved=True, source="note")
     ```
     Determine `target_type` from `table_name`: `'post'` (including rants), `'gist'`, `'project'`.  
   - In `create_comment_record()` (after line 361):  
     ```python
     if has_note(content):
         set_bookmark(request, user, parent_target_type, parent_target_uid, saved=True, source="note")
     ```
     `parent_target_type` and `parent_target_uid` are already available in the function (they are parameters or derived from the comment record).

4. **Update saved listings endpoint to support `source` filter**  
   - File: `devplacepy/routers/bookmarks.py`  
   - In `GET /bookmarks/saved`, add optional query parameter `source: str = None`.  
   - When `source` is provided, append `source=source` to the DB query.  
   - Pass `source` to template context.

5. **Update saved page template with filter tab**  
   - File: `devplacepy/templates/saved.html`  
   - At top of listing, add two tabs: "All" (`?source=`) and "Notes" (`?source=note`).  
   - Active tab based on current `source` query param.  
   - Keep same pagination and item rendering.

6. **Add Devii agent action `list_notes`**  
   - File: `devplacepy/services/devii/actions/catalog/engagement.py`  
   - Add action definition that calls bookmarks listing with `source="note"`.  
   - Register action in catalog.

7. **Update API docs**  
   - File: `devplacepy/docs_api/groups/social_actions.py`  
   - Add entry for notes listing (same schema as bookmarks, but filtered).

8. **Write tests**  
   - Create `tests/api/notes/` with one test that verifies:  
     - Creating a post with `@note` creates a bookmark with `source="note"`.  
     - `GET /bookmarks/saved?source=note` returns that item.  
     - `GET /bookmarks/saved` (no filter) returns all bookmarks including notes.  
   - Create `tests/e2e/notes/` mirroring existing bookmark e2e pattern:  
     - Use Playwright to sign up, create post with `@note`, navigate to saved page, click "Notes" tab, verify item appears.

9. **Lint and unit tests**  
   - Run `ruff check .` – ensure zero new violations.  
   - Run `pip install -e '.[dev]' -q && make test-unit` – ensure all tests pass.

### Definition of Done

- [ ] Database migration adds `source` column (default `'manual'`) and index `idx_bookmarks_source`.  
- [ ] `set_bookmark()` accepts `source` parameter; all existing calls pass `source="manual"`.  
- [ ] Creating a post/gist/project/rant containing `@note` auto-creates a bookmark with `source="note"`.  
- [ ] Creating a comment containing `@note` auto-creates a bookmark for the parent content (not the comment).  
- [ ] `GET /bookmarks/saved?source=note` returns only notes; no `source` returns all.  
- [ ] Saved page template shows "All" and "Notes" tabs; "Notes" tab shows noted items.  
- [ ] Devii agent can list notes via `list_notes` action.  
- [ ] API docs include notes listing under social actions.  
- [ ] API tests and e2e tests for notes pass.  
- [ ] `ruff check .` passes with zero errors.  
- [ ] `make test-unit` passes (all existing + new tests).