search: saved searches via bookmark button

Small bookmark icon in the search header bar opens a popup listing
localStorage-persisted search strings. Clicking an entry fills the
input and runs the search; the x button deletes it; "save current
search" at the bottom saves the active input (no dupes). List
persists across sessions, no server round-trip.

Tests: 6 cases covering button/popup toggle, save + recall, delete,
save-current-button, and duplicate rejection. All snapshot/restore
localStorage in try/finally so they don't leak into user data or
cross-test state.

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

public/index.php

@@ -2051,6 +2051,15 @@ if (str_starts_with($route, '/api/')) {
                     <i class="ph ph-magnifying-glass text-t-accent text-base"></i>
                     <input type="text" id="search-input" placeholder="search cards..." class="flex-1 bg-transparent text-t-bright text-sm placeholder:text-t-dim font-mono" autocomplete="off" spellcheck="false">
                     <select id="search-bucket-filter" class="bg-t-bg border border-t-border text-t-muted text-[10px] font-pixel px-2 py-1 rounded-sm focus:border-t-accent focus:outline-none cursor-pointer"><option value="">all buckets</option></select>
+                    <div class="relative">
+                        <button id="search-saved-btn" class="flex items-center gap-1.5 px-2.5 py-1 text-xs border border-t-border text-t-muted hover:border-t-accent hover:text-t-accent transition-colors" data-tip="saved searches">
+                            <i class="ph ph-bookmark-simple text-sm"></i>
+                        </button>
+                        <div id="search-saved-popup" class="hidden absolute right-0 top-full mt-1 min-w-[220px] max-h-[280px] bg-t-surface border border-t-border shadow-2xl z-50 flex flex-col" style="border-radius:var(--ui-radius-modal,4px)">
+                            <div id="search-saved-list" class="overflow-y-auto flex-1"></div>
+                            <button id="search-saved-add" class="w-full text-left px-3 py-2 text-[10px] font-pixel text-t-accent border-t border-t-border hover:bg-t-raised transition-colors"><i class="ph ph-plus text-xs"></i> save current search</button>
+                        </div>
+                    </div>
                     <button id="search-replace-toggle" class="flex items-center gap-1.5 px-2.5 py-1 text-xs border border-t-border text-t-muted hover:border-t-accent hover:text-t-accent transition-colors" data-help="Replace mode\nSearch and replace text across all\nmatching cards. Ctrl+Shift+H to open.">
                         <i class="ph ph-swap text-sm"></i><span class="font-pixel text-[10px]">Replace</span>
                     </button>