detail: optional bucket-switch on open from search / link

New toggle under Settings → Behavior → Interactions: "Switch to
card's bucket on open (search / link)". When enabled, openDetail
calls activateBucket(card.bucket_id) so the board and bucket bar
update to show the card's context. Skipped when already on 'all'
or the correct bucket. Default off.

Uses activateBucket() (from buckets.js) instead of raw state
assignment so the bucket-bar highlight tracks the switch.

Tests: two cases — setting on switches activeBucket + verifies the
bucket-tab.active in the bar matches; setting off leaves the
bucket unchanged. Both create/delete probe cards in try/finally
and restore the setting + activeBucket in afterEach.

Bumps to 1.9.27.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

public/index.php

@@ -1926,6 +1926,7 @@ if (str_starts_with($route, '/api/')) {
                                 </div>
                                 <div class="toggle-row" data-toggle="setting-confirm-delete"><span class="toggle-label">Confirm before delete</span><div class="toggle-switch" id="setting-confirm-delete"></div></div>
                                 <div class="toggle-row" data-toggle="setting-auto-save"><span class="toggle-label">Auto-save on close (editor)</span><div class="toggle-switch" id="setting-auto-save"></div></div>
+                                <div class="toggle-row" data-toggle="setting-open-switches-bucket"><span class="toggle-label">Switch to card's bucket on open (search / link)</span><div class="toggle-switch" id="setting-open-switches-bucket"></div></div>
                             </div>
                         </div>
                     </div>