Add settings tooltips and search to the web UI

Help users quickly find settings and understand how each one works.

Tooltips: a new delegated controller (static/v3/js/tooltips.js) drives an
accessible (i) info tooltip that appears on hover, keyboard focus, and tap.
A shared `help_tip` Jinja macro (partials/_macros.html) emits the trigger;
the plugin config macro and the core settings partials now surface help
text through it. Per the design, the always-visible field help paragraphs
are folded into the tooltip to declutter the forms, and the hardware/display
settings carry authored detail (default, range, recommendation).

Search: a global header search box finds settings across every settings tab
— even ones not yet opened — via a lazy client-side index built by scanning
the same field markup (static/v3/js/settings-search.js). Selecting a result
switches tabs, waits for the field to load, then scrolls to and flashes it.
A per-tab filter box hides non-matching fields on the current tab.

Plugin settings get tooltips for free by reusing each field's schema
`description`; every settings field also gets a stable `setting-<tab>-<key>`
anchor id for search navigation.

Styling uses the existing --color-* theme vars so light/dark mode both work,
and honors prefers-reduced-motion. Adds Flask render smoke tests that assert
each settings partial ships tooltips, anchors, and a filter box.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014gZxznuxw8L92FUMBN3Nqz

web_interface/templates/v3/partials/schedule.html

@@ -1,9 +1,12 @@
+{% import 'v3/partials/_macros.html' as ui %}
 <div class="bg-white rounded-lg shadow p-6">
     <div class="border-b border-gray-200 pb-4 mb-6">
         <h2 class="text-lg font-semibold text-gray-900">Schedule Settings</h2>
         <p class="mt-1 text-sm text-gray-600">Configure when the LED matrix display should be active. You can set global hours or customize times for each day of the week.</p>
     </div>
 
+    {{ ui.settings_filter() }}
+
     <form id="schedule_form"
           hx-post="/api/v3/config/schedule"
           hx-ext="json-enc"
@@ -42,9 +45,9 @@
           class="space-y-6">
 
         <!-- Dim Brightness Level -->
-        <div class="bg-gray-50 rounded-lg p-4 mb-4">
+        <div class="form-group bg-gray-50 rounded-lg p-4 mb-4" id="setting-schedule-dim_brightness" data-setting-key="dim_schedule.dim_brightness">
             <label for="dim_brightness" class="block text-sm font-medium text-gray-700 mb-2">
-                Dim Brightness Level
+                Dim Brightness Level{{ ui.help_tip('Brightness the display drops to during dim hours (0–100%).\nApplies only while the display is on. Your normal brightness is currently ' ~ normal_brightness ~ '%.', 'Dim Brightness Level') }}
             </label>
             <div class="flex items-center space-x-4">
                 <input type="range"
@@ -59,7 +62,6 @@
                     {{ dim_schedule_config.dim_brightness | default(30) }}%
                 </span>
             </div>
-            <p class="mt-1 text-xs text-gray-500">Current normal brightness: {{ normal_brightness }}%</p>
         </div>
 
         <!-- Dim Schedule Picker Widget Container -->