Rework API input CSS: segments, remove led_count, HAOS light, test preview

API Input CSS rework:
- Remove led_count field from ApiInputColorStripSource (always auto-sizes)
- Add segment-based payload: solid, per_pixel, gradient modes
- Segments applied in order (last wins on overlap), auto-grow buffer
- Backward compatible: legacy {"colors": [...]} still works
- Pydantic validation: mode-specific field requirements

Test preview:
- Enable test preview button on api_input cards
- Hide LED/FPS controls for api_input (sender controls those)
- Show input source selector for all CSS tests (preselected)
- FPS sparkline chart using shared createFpsSparkline (same as target cards)
- Server only sends frames when push_generation changes (no idle frames)

HAOS integration:
- New light.py: ApiInputLight entity per api_input source (RGB + brightness)
- turn_on pushes solid segment, turn_off pushes fallback color
- Register wled_screen_controller.set_leds service for arbitrary segments
- New services.yaml with field definitions
- Coordinator: push_colors() and push_segments() methods
- Platform.LIGHT added to platforms list

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

server/src/wled_controller/static/js/app.js

@@ -182,12 +182,14 @@ import { switchTab, initTabs, startAutoRefresh, handlePopState } from './feature
 import { navigateToCard } from './core/navigation.js';
 import { openCommandPalette, closeCommandPalette, initCommandPalette } from './core/command-palette.js';
 import {
-    openSettingsModal, closeSettingsModal, downloadBackup, handleRestoreFileSelected,
+    openSettingsModal, closeSettingsModal, switchSettingsTab,
+    downloadBackup, handleRestoreFileSelected,
     saveAutoBackupSettings, restoreSavedBackup, downloadSavedBackup, deleteSavedBackup,
     restartServer, saveMqttSettings,
     loadApiKeysList,
     downloadPartialExport, handlePartialImportFileSelected,
     connectLogViewer, disconnectLogViewer, clearLogViewer, applyLogFilter,
+    openLogOverlay, closeLogOverlay,
     loadLogLevel, setLogLevel,
 } from './features/settings.js';
 
@@ -522,9 +524,10 @@ Object.assign(window, {
     openCommandPalette,
     closeCommandPalette,
 
-    // settings (backup / restore / auto-backup / MQTT / partial export-import / api keys / log level)
+    // settings (tabs / backup / restore / auto-backup / MQTT / partial export-import / api keys / log level)
     openSettingsModal,
     closeSettingsModal,
+    switchSettingsTab,
     downloadBackup,
     handleRestoreFileSelected,
     saveAutoBackupSettings,
@@ -540,6 +543,8 @@ Object.assign(window, {
     disconnectLogViewer,
     clearLogViewer,
     applyLogFilter,
+    openLogOverlay,
+    closeLogOverlay,
     loadLogLevel,
     setLogLevel,
 });
@@ -569,8 +574,11 @@ document.addEventListener('keydown', (e) => {
     }
 
     if (e.key === 'Escape') {
-        // Close in order: overlay lightboxes first, then modals via stack
-        if (document.getElementById('display-picker-lightbox').classList.contains('active')) {
+        // Close in order: log overlay > overlay lightboxes > modals via stack
+        const logOverlay = document.getElementById('log-overlay');
+        if (logOverlay && logOverlay.style.display !== 'none') {
+            closeLogOverlay();
+        } else if (document.getElementById('display-picker-lightbox').classList.contains('active')) {
             closeDisplayPicker();
         } else if (document.getElementById('image-lightbox').classList.contains('active')) {
             closeLightbox();