Move color strip sources from Targets tab to Sources tab

- Remove csColorStrips CardSection from targets.js, add to streams.js
- Add color_strip sub-tab with tree nav entry between Picture and Audio
- Update navigateToCard refs in target cards and command palette
- Update tutorial steps: remove led-css from targets, add color_strip to sources
- Add i18n keys for streams.group.color_strip and tour.src.color_strip

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

server/src/wled_controller/static/js/features/tutorials.js

@@ -46,7 +46,6 @@ const dashboardTutorialSteps = [
 const targetsTutorialSteps = [
     { selector: '[data-tree-group="led_group"]', textKey: 'tour.tgt.led_tab', position: 'right' },
     { selector: '[data-card-section="led-devices"]', textKey: 'tour.tgt.devices', position: 'bottom' },
-    { selector: '[data-card-section="led-css"]', textKey: 'tour.tgt.css', position: 'bottom' },
     { selector: '[data-card-section="led-targets"]', textKey: 'tour.tgt.targets', position: 'bottom' },
     { selector: '[data-tree-group="kc_group"]', textKey: 'tour.tgt.kc_tab', position: 'right' }
 ];
@@ -56,6 +55,7 @@ const sourcesTourSteps = [
     { selector: '[data-card-section="raw-templates"]', textKey: 'tour.src.templates', position: 'bottom' },
     { selector: '#streams-tree-nav [data-tree-leaf="static_image"]', textKey: 'tour.src.static', position: 'right' },
     { selector: '#streams-tree-nav [data-tree-leaf="processed"]', textKey: 'tour.src.processed', position: 'right' },
+    { selector: '#streams-tree-nav [data-tree-leaf="color_strip"]', textKey: 'tour.src.color_strip', position: 'right' },
     { selector: '#streams-tree-nav [data-tree-leaf="audio"]', textKey: 'tour.src.audio', position: 'right' },
     { selector: '#streams-tree-nav [data-tree-leaf="value"]', textKey: 'tour.src.value', position: 'right' },
     { selector: '#streams-tree-nav [data-tree-leaf="sync"]', textKey: 'tour.src.sync', position: 'right' }