my_sea_gate burger; _bud_apparatus shared shell; CI #344 tray-anchor fix — TDD

Continuation of the burger sprint into the my-sea gatekeeper + a couple companion cleanups the visual + CI runs surfaced.

## my_sea_gate.html burger

`templates/apps/gameboard/_partials/_room_burger.html` → `_burger.html` (git mv) — now lives at a non-room-scoped path since it's reused across templates. Updated room.html's include path.

`templates/apps/gameboard/my_sea_gate.html` — includes `_burger.html` + loads `burger-btn.js`. Burger renders unconditionally on the my-sea gatekeeper, same affordance as the room gatekeeper.

`apps/gameboard/tests/integrated/test_views.py::MySeaGateViewTest` — new `test_gate_view_renders_burger_btn_and_fan` IT asserts burger_btn + burger_fan + 5 sub-btns w. correct ids + burger-btn.js loaded on `/gameboard/my-sea/gate/`.

## Burger fade rule reinstated

`static_src/scss/_burger.scss` — `html.bud-open #id_burger_btn { opacity: 0; pointer-events: none; }` reinstated, scoped to landscape only. User-confirmed: even after the z-index drop the burger needs to disappear when bud_panel is open in landscape (panel + bud_ok races vs. burger pointer-events). Portrait keeps burger visible since the panel sits BELOW the burger w. no overlap.

## "friend@example.com" → "bud@example.com" placeholder

Renamed in 4 bud-panel templates + the FT asserting it:
- `templates/apps/gameboard/_partials/_my_sea_bud_panel.html`
- `templates/apps/billboard/_partials/_bud_panel.html`
- `templates/apps/billboard/_partials/_bud_invite_panel.html`
- `templates/apps/billboard/_partials/_bud_add_panel.html`
- `functional_tests/test_core_sharing.py`

"bud" matches the broader naming convention (bud_btn, my-buds, share-w.-a-bud, etc.) — `friend` was an outlier.

## _bud_apparatus.html shared shell refactor

New `templates/apps/billboard/_partials/_bud_apparatus.html` — single shared markup partial for the four bud-btn use cases. Contains btn + panel + input + OK + (optional) suggestions div + bud-btn.js script. Each of the 4 specific partials becomes a thin wrapper that `{% include %}`s the shell + renders its own `<script>bindBudBtn({...})</script>` block w. per-use-case submitUrl / onSuccess / duplicateTargetSelector.

Context vars accepted by the shell:
- `aria_label` — string for #id_bud_btn aria-label
- `sharer_name` — optional; renders `data-sharer-name=` on #id_bud_panel (post-share only)
- `include_suggestions` — bool; renders suggestions div + autocomplete script (false on my_buds where the pool == request.user.buds == nothing useful to suggest)

Per-call wrappers are now ~10-50 lines instead of 30-120 lines of duplicate markup. Behaviour is identical; only DRY-ed up.

## CI #344 tray-anchor regression fix

`apps/epic/static/apps/epic/tray.js` — `_computeBounds` in landscape used `id_gear_btn || id_kit_btn` as the bottom anchor (wrap height = anchor.top). After the burger sprint relocated kit_btn to the TOP of the right sidebar (top:0.5rem), kit_btn.top ≈ 8px → wrap.height collapsed to 8px → tray couldn't slide → `test_dragging_tray_btn_down_opens_tray_in_landscape` failed.

Fix: anchor fallback chain is now `id_burger_btn || id_bud_btn` (the new bottom-anchored btns) → `window.innerHeight - 3.5rem` reserved fallback (for pages that have neither). Burger renders unconditionally on room.html so the SIG_SELECT tray test now finds its anchor + lays out the wrap correctly.

## Verification

- IT+UT 1357 green (+1 from MySeaGateViewTest burger).
- Jasmine specs green.
- `test_dragging_tray_btn_down_opens_tray_in_landscape` green (was the CI #344 failure).

Code architected by Disco DeDisco <discodedisco@outlook.com>
Git commit message Co-Authored-By:
Claude Sonnet 4.6 <noreply@anthropic.com>

src/functional_tests/test_core_sharing.py

@@ -41,7 +41,7 @@ class SharingTest(FunctionalTest):
         share_box = post_page.get_share_box()
         self.assertEqual(
             share_box.get_attribute("placeholder"),
-            "friend@example.com or username",
+            "bud@example.com or username",
         )
 
         post_page.share_post_with("alice@test.io")