Add WebUI navigation improvements: keyboard shortcuts, hash routing, command palette, cross-entity links

- Keyboard shortcuts: Ctrl+1-4 for tab switching
- URL hash routing: #tab/subtab format with browser back/forward support
- Tab count badges: running targets and active profiles counts
- Cross-entity quick links: clickable references navigate to related cards
- Command palette (Ctrl+K): global search across all entities with keyboard navigation
- Expand/collapse all sections: buttons in sub-tab bars
- Sticky section headers: headers pin while scrolling long card grids
- Improved section filter: better styling with reset button

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/static/locales/en.json

@@ -253,6 +253,9 @@
   "common.edit": "Edit",
   "common.clone": "Clone",
   "section.filter.placeholder": "Filter...",
+  "section.filter.reset": "Clear filter",
+  "section.expand_all": "Expand all sections",
+  "section.collapse_all": "Collapse all sections",
   "streams.title": "\uD83D\uDCFA Sources",
   "streams.description": "Sources define the capture pipeline. A raw source captures from a display using a capture template. A processed source applies postprocessing to another source. Assign sources to devices.",
   "streams.group.raw": "Screen Capture",
@@ -849,5 +852,20 @@
   "value_source.error.name_required": "Please enter a name",
   "targets.brightness_vs": "Brightness Source:",
   "targets.brightness_vs.hint": "Optional value source that dynamically controls brightness each frame (overrides device brightness)",
-  "targets.brightness_vs.none": "None (device brightness)"
+  "targets.brightness_vs.none": "None (device brightness)",
+
+  "search.placeholder": "Search entities... (Ctrl+K)",
+  "search.loading": "Loading...",
+  "search.no_results": "No results found",
+  "search.group.devices": "Devices",
+  "search.group.targets": "LED Targets",
+  "search.group.kc_targets": "Key Colors Targets",
+  "search.group.css": "Color Strip Sources",
+  "search.group.profiles": "Profiles",
+  "search.group.streams": "Picture Streams",
+  "search.group.capture_templates": "Capture Templates",
+  "search.group.pp_templates": "Post-Processing Templates",
+  "search.group.pattern_templates": "Pattern Templates",
+  "search.group.audio": "Audio Sources",
+  "search.group.value": "Value Sources"
 }