Merge templates into Streams tab, rename app to WLED Grab

- Merge Capture Templates and Processing Templates main tabs into Picture
  Streams sub-tabs (Screen Capture shows streams + engine templates,
  Processed shows streams + filter templates)
- Rename "Capture Templates" to "Engine Templates" and "Processing
  Templates" to "Filter Templates" across all locale strings
- Rename "Picture Streams" tab to "Streams" throughout UI and locales
- Rename "WLED Screen Controller" to "WLED Grab" across all files
- Add subtab section headers and styling for merged template views
- Remove add card labels, keeping only plus icon for cleaner UI

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

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

@@ -1,5 +1,5 @@
 {
-  "app.title": "WLED Screen Controller",
+  "app.title": "WLED Grab",
   "app.version": "Version:",
   "theme.toggle": "Toggle theme",
   "locale.change": "Change language",
@@ -7,7 +7,7 @@
   "auth.logout": "Logout",
   "auth.authenticated": "● Authenticated",
   "auth.title": "Login to WLED Controller",
-  "auth.message": "Please enter your API key to authenticate and access the WLED Screen Controller.",
+  "auth.message": "Please enter your API key to authenticate and access the WLED Grab.",
   "auth.label": "API Key:",
   "auth.placeholder": "Enter your API key...",
   "auth.hint": "Your API key will be stored securely in your browser's local storage.",
@@ -35,12 +35,12 @@
   "displays.picker.title": "Select a Display",
   "displays.picker.select": "Select display...",
   "displays.picker.click_to_select": "Click to select this display",
-  "templates.title": "\uD83C\uDFAF Capture Templates",
+  "templates.title": "\uD83D\uDCC4 Engine Templates",
   "templates.description": "Capture templates define how the screen is captured. Each template uses a specific capture engine (MSS, DXcam, WGC) with custom settings. Assign templates to devices for optimal performance.",
   "templates.loading": "Loading templates...",
   "templates.empty": "No capture templates configured",
-  "templates.add": "Add Capture Template",
-  "templates.edit": "Edit Capture Template",
+  "templates.add": "Add Engine Template",
+  "templates.edit": "Edit Engine Template",
   "templates.name": "Template Name:",
   "templates.name.placeholder": "My Custom Template",
   "templates.description.label": "Description (optional):",
@@ -154,7 +154,7 @@
   "settings.display_index.hint": "Which screen to capture for this device",
   "settings.fps": "Target FPS:",
   "settings.fps.hint": "Target frames per second (10-90)",
-  "settings.capture_template": "Capture Template:",
+  "settings.capture_template": "Engine Template:",
   "settings.capture_template.hint": "Screen capture engine and configuration for this device",
   "settings.button.cancel": "Cancel",
   "settings.health_interval": "Health Check Interval (s):",
@@ -198,14 +198,15 @@
   "confirm.no": "No",
   "common.delete": "Delete",
   "common.edit": "Edit",
-  "streams.title": "\uD83D\uDCFA Picture Streams",
-  "streams.description": "Picture streams define the capture pipeline. A raw stream captures from a display using a capture template. A processed stream applies postprocessing to another stream. Assign streams to devices.",
+  "streams.title": "\uD83D\uDCFA Streams",
+  "streams.description": "Streams define the capture pipeline. A raw stream captures from a display using a capture template. A processed stream applies postprocessing to another stream. Assign streams to devices.",
   "streams.group.raw": "Screen Capture",
   "streams.group.processed": "Processed",
-  "streams.add": "Add Picture Stream",
+  "streams.section.streams": "\uD83D\uDCFA Streams",
+  "streams.add": "Add Stream",
   "streams.add.raw": "Add Screen Capture",
   "streams.add.processed": "Add Processed Stream",
-  "streams.edit": "Edit Picture Stream",
+  "streams.edit": "Edit Stream",
   "streams.edit.raw": "Edit Screen Capture",
   "streams.edit.processed": "Edit Processed Stream",
   "streams.name": "Stream Name:",
@@ -214,10 +215,10 @@
   "streams.type.raw": "Screen Capture",
   "streams.type.processed": "Processed",
   "streams.display": "Display:",
-  "streams.capture_template": "Capture Template:",
+  "streams.capture_template": "Engine Template:",
   "streams.target_fps": "Target FPS:",
   "streams.source": "Source Stream:",
-  "streams.pp_template": "Processing Template:",
+  "streams.pp_template": "Filter Template:",
   "streams.description_label": "Description (optional):",
   "streams.description_placeholder": "Describe this stream...",
   "streams.created": "Stream created successfully",
@@ -227,17 +228,17 @@
   "streams.error.load": "Failed to load streams",
   "streams.error.required": "Please fill in all required fields",
   "streams.error.delete": "Failed to delete stream",
-  "streams.test.title": "Test Picture Stream",
+  "streams.test.title": "Test Stream",
   "streams.test.run": "🧪 Run Test",
   "streams.test.running": "Testing stream...",
   "streams.test.duration": "Capture Duration (s):",
   "streams.test.error.failed": "Stream test failed",
-  "postprocessing.title": "\uD83C\uDFA8 Processing Templates",
+  "postprocessing.title": "\uD83D\uDCC4 Filter Templates",
   "postprocessing.description": "Processing templates define image filters and color correction. Assign them to processed picture streams for consistent postprocessing across devices.",
-  "postprocessing.add": "Add Processing Template",
-  "postprocessing.edit": "Edit Processing Template",
+  "postprocessing.add": "Add Filter Template",
+  "postprocessing.edit": "Edit Filter Template",
   "postprocessing.name": "Template Name:",
-  "postprocessing.name.placeholder": "My Processing Template",
+  "postprocessing.name.placeholder": "My Filter Template",
   "filters.select_type": "Select filter type...",
   "filters.add": "Add Filter",
   "filters.remove": "Remove",
@@ -255,20 +256,20 @@
   "postprocessing.created": "Template created successfully",
   "postprocessing.updated": "Template updated successfully",
   "postprocessing.deleted": "Template deleted successfully",
-  "postprocessing.delete.confirm": "Are you sure you want to delete this processing template?",
+  "postprocessing.delete.confirm": "Are you sure you want to delete this filter template?",
   "postprocessing.error.load": "Failed to load processing templates",
   "postprocessing.error.required": "Please fill in all required fields",
   "postprocessing.error.delete": "Failed to delete processing template",
   "postprocessing.config.show": "Show settings",
-  "postprocessing.test.title": "Test Processing Template",
+  "postprocessing.test.title": "Test Filter Template",
   "postprocessing.test.source_stream": "Source Stream:",
   "postprocessing.test.running": "Testing processing template...",
   "postprocessing.test.error.no_stream": "Please select a source stream",
   "postprocessing.test.error.failed": "Processing template test failed",
   "device.button.stream_selector": "Stream Settings",
   "device.stream_settings.title": "📺 Stream Settings",
-  "device.stream_selector.label": "Picture Stream:",
-  "device.stream_selector.hint": "Select a picture stream that defines what this device captures and processes",
+  "device.stream_selector.label": "Stream:",
+  "device.stream_selector.hint": "Select a stream that defines what this device captures and processes",
   "device.stream_selector.none": "-- No stream assigned --",
   "device.stream_selector.saved": "Stream settings updated",
   "device.stream_settings.border_width": "Border Width (px):",