## Implementation Plan: Shareable Comment Permalinks

### Overview

Add a `data-share` button to comment action bars, enabling clipboard-copy of `{parent_url}#comment-{uid}`. No backend, JS, CSS, test, or configuration changes required. Three files, ~8 lines total.

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### Changes

#### 1. `devplacepy/templating.py`

Add import and register `resolve_object_url` as a Jinja global.

- At the top of the file, add:  
  `from devplacepy.database.content import resolve_object_url`
- In the globals registration block (around line 215), add:  
  `templates.env.globals["resolve_object_url"] = resolve_object_url`

#### 2. `devplacepy/templates/_comment_section.html`

Compute the parent URL from the available `target_type`/`target_uid` variables and pass it to the `render_comment` macro.

- After the `{% set target_uid,... %}` block (which comes from the includer), insert:  
  `{% set parent_url = resolve_object_url(target_type, target_uid) %}`
- Change the render call at line 7:  
  `{{ render_comment(item, 0, parent_url) }}`

#### 3. `devplacepy/templates/_comment.html`

Thread the `parent_url` parameter through the macro chain and add the share button.

- `render_comment(item, depth=0, parent_url=None)` – add `parent_url=None`
- `comment_cell(item, depth, parent_author=None, parent_url=None)` – add `parent_url=None`
- `render_comment_flat(item, depth, parent_author, parent_url=None)` – add `parent_url=None`
- In `comment_cell`, inside the `{% call render_comment_cell(item, ...) %}` block, pass `parent_url` through:  
  `{{ comment_cell(item, visual_depth, parent_url=parent_url) }}` (check actual call chain: `render_comment` calls `comment_cell` with two args; add `parent_url=parent_url`)
- In `render_comment_flat`, pass `parent_url` to `comment_cell` accordingly.
- Inside the `.comment-actions` div (after the Reply button, before the Edit button), add:  
  ```html
  <button type="button" class="comment-action-btn" 
    data-share="{{ parent_url }}#comment-{{ item.comment['uid'] }}">
    <span class="icon">🔗</span><span class="label"> Share</span>
  </button>
  ```

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### Definition of Done

- [ ] The three files are modified exactly as specified above.
- [ ] Project lint passes: `pip install -q ruff && ruff check .` (exit 0).
- [ ] Project unit tests pass: `pip install -e '.[dev]' -q && make test-unit` (exit 0).
- [ ] Share button appears on every comment visible in the UI (post, news, gist, project detail pages).
- [ ] Clicking the share button copies `{page_url}#comment-{uid}` to clipboard and shows a "Copied!" toast.
- [ ] Navigating directly to `.../post/example#comment-abc` scrolls to the comment and applies the `.comment-highlight` fade animation.