Fix theme selection bug and update onboarding with AppTheme picker

- Change Theme enum from Int to String raw values to fix theme selection bug
- Replace OnboardingStyle icon/color pickers with unified AppTheme grid
- Remove visible text labels from voting layouts while keeping accessibility labels (WCAG 2.1 AA compliant)
- Update widget voting views to use icons only with proper accessibility support
- Consolidate app icons to single unified icon set

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Feels/Localizable.xcstrings

@@ -1776,6 +1776,7 @@
     },
     "Choose your favorite style" : {
       "comment" : "A subtitle under the title \"Make it yours\" in the OnboardingStyle view.",
+      "extractionState" : "stale",
       "isCommentAutoGenerated" : true,
       "localizations" : {
         "de" : {
@@ -1816,6 +1817,10 @@
         }
       }
     },
+    "Choose your vibe" : {
+      "comment" : "A title displayed on the onboarding screen, encouraging users to choose their preferred theme.",
+      "isCommentAutoGenerated" : true
+    },
     "Choose Your Vibe" : {
       "comment" : "A title displayed at the top of the view, encouraging the user to choose a theme.",
       "isCommentAutoGenerated" : true
@@ -4543,6 +4548,10 @@
       "comment" : "A description of how themes work.",
       "isCommentAutoGenerated" : true
     },
+    "Each theme sets your colors, icons, and layouts" : {
+      "comment" : "A description under the title of the view, explaining what each theme does.",
+      "isCommentAutoGenerated" : true
+    },
     "Edit" : {
       "comment" : "A button label that triggers the editing of a journal note.",
       "isCommentAutoGenerated" : true,
@@ -5837,6 +5846,7 @@
     },
     "Icon Style" : {
       "comment" : "A section header that says \"Icon Style\".",
+      "extractionState" : "stale",
       "isCommentAutoGenerated" : true,
       "localizations" : {
         "de" : {
@@ -6396,6 +6406,7 @@
     },
     "Make it yours" : {
       "comment" : "A title displayed in the onboarding view, encouraging users to personalize their interface.",
+      "extractionState" : "stale",
       "isCommentAutoGenerated" : true,
       "localizations" : {
         "de" : {
@@ -6651,6 +6662,7 @@
     },
     "Mood Colors" : {
       "comment" : "A section header that lists the mood colors.",
+      "extractionState" : "stale",
       "isCommentAutoGenerated" : true,
       "localizations" : {
         "de" : {
@@ -13789,6 +13801,7 @@
     },
     "Wednesday - 10th" : {
       "comment" : "A label displayed above the date of a mood entry.",
+      "extractionState" : "stale",
       "isCommentAutoGenerated" : true,
       "localizations" : {
         "de" : {
@@ -14170,6 +14183,7 @@
     },
     "You can change these anytime in Customize" : {
       "comment" : "A hint displayed below the options to change the app's style and color theme.",
+      "extractionState" : "stale",
       "isCommentAutoGenerated" : true,
       "localizations" : {
         "de" : {
@@ -14210,6 +14224,10 @@
         }
       }
     },
+    "You can change this anytime in Customize" : {
+      "comment" : "A hint displayed below the grid of theme cards, encouraging the user to change their theme settings.",
+      "isCommentAutoGenerated" : true
+    },
     "You can still customize individual settings after applying a theme" : {
       "comment" : "A note explaining that users can still customize individual settings after applying a theme.",
       "isCommentAutoGenerated" : true