feat: game integration system

Receive real-time events from games (CS2, Dota 2, LoL, etc.) and drive
LED effects through the existing color strip and value source pipelines.

Core:
- GameEventBus (thread-safe pub/sub) with standardized 23-type event vocabulary
- GameAdapter ABC + AdapterRegistry + MappingAdapter (YAML-driven)
- Built-in adapters: CS2 GSI, Dota 2 GSI, LoL Live Client, Generic Webhook
- Community YAML adapters: Minecraft, Valorant, Rocket League
- GameEventColorStripStream with 5 effects (flash/pulse/sweep/color_shift/breathing)
- GameEventValueSource with EMA smoothing and timeout
- 4 built-in effect presets (FPS Combat, MOBA Health, Racing, Generic Alert)
- Auto-setup for Valve GSI games (Steam path detection, cfg file writing)
- Demo capture engine exposed to non-demo mode

Frontend:
- Game tab in Streams tree navigation with integration cards
- Game integration editor modal with adapter picker, config fields, event mappings
- game_event source type in CSS and ValueSource editors
- Setup instructions overlay (markdown rendered)
- Live event monitor and connection test

API:
- Full CRUD for game integrations
- Event ingestion endpoint (adapter-level auth)
- Adapter metadata, presets, auto-setup, status/diagnostics endpoints

server/src/wled_controller/templates/modals/css-editor.html

@@ -38,6 +38,7 @@
                         <option value="weather" data-i18n="color_strip.type.weather">Weather</option>
                         <option value="processed" data-i18n="color_strip.type.processed">Processed</option>
                         <option value="key_colors" data-i18n="color_strip.type.key_colors">Key Colors</option>
+                        <option value="game_event" data-i18n="color_strip.type.game_event">Game Event</option>
                     </select>
                 </div>
 
@@ -689,6 +690,46 @@
                     </div>
                 </div>
 
+                <!-- Game Event section -->
+                <div id="css-editor-game-event-section" style="display:none">
+                    <div class="form-group">
+                        <div class="label-row">
+                            <label for="css-editor-game-integration" data-i18n="color_strip.game_event.integration">Game Integration:</label>
+                            <button type="button" class="hint-toggle" onclick="toggleHint(this)" title="?" data-i18n-aria-label="aria.hint">?</button>
+                        </div>
+                        <small class="input-hint" style="display:none" data-i18n="color_strip.game_event.integration.hint">Select the game integration that provides events for this source.</small>
+                        <select id="css-editor-game-integration">
+                            <option value="">—</option>
+                        </select>
+                    </div>
+                    <div class="form-group">
+                        <div class="label-row">
+                            <label data-i18n="color_strip.game_event.idle_color">Idle Color:</label>
+                            <button type="button" class="hint-toggle" onclick="toggleHint(this)" title="?" data-i18n-aria-label="aria.hint">?</button>
+                        </div>
+                        <small class="input-hint" style="display:none" data-i18n="color_strip.game_event.idle_color.hint">LED color when no game events are active.</small>
+                        <div id="css-editor-game-event-idle-color-container"></div>
+                    </div>
+                    <div class="form-group">
+                        <div class="label-row">
+                            <label data-i18n="color_strip.game_event.event_mappings">Event Mappings:</label>
+                            <button type="button" class="hint-toggle" onclick="toggleHint(this)" title="?" data-i18n-aria-label="aria.hint">?</button>
+                        </div>
+                        <small class="input-hint" style="display:none" data-i18n="color_strip.game_event.event_mappings.hint">Override or add event-to-effect mappings for this source. These supplement the integration-level mappings.</small>
+                        <div class="gi-mapping-preset-row">
+                            <select id="css-editor-ge-mapping-preset" onchange="onCSSGameMappingPresetChange()">
+                                <option value="" data-i18n="game_integration.preset.select">Load preset...</option>
+                                <option value="fps_combat" data-i18n="game_integration.preset.fps_combat">FPS Combat</option>
+                                <option value="moba_health" data-i18n="game_integration.preset.moba_health">MOBA Health</option>
+                            </select>
+                        </div>
+                        <div id="css-editor-ge-mappings-list" class="gi-mappings-container"></div>
+                        <button type="button" class="btn btn-secondary btn-sm" onclick="addCSSGameMapping()" style="margin-top:6px">
+                            <span data-i18n="game_integration.mapping.add">+ Add Mapping</span>
+                        </button>
+                    </div>
+                </div>
+
                 <!-- Shared LED count field -->
                 <div id="css-editor-led-count-group" class="form-group">
                     <div class="label-row">