Update signing configuration to use 88oakapps.feels identifiers

- Update App Group IDs from group.com.tt.feels to group.com.88oakapps.feels
- Update iCloud container IDs from iCloud.com.tt.feels to iCloud.com.88oakapps.feels
- Sync code constants with entitlements across all targets (iOS, Watch, Widget)
- Update documentation in CLAUDE.md and PROJECT_OVERVIEW.md

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

Shared/Persisence/ExtensionDataProvider.swift

@@ -47,9 +47,9 @@ final class ExtensionDataProvider {
             // Watch uses CloudKit for automatic sync with iPhone
             let cloudKitContainerID: String
             #if DEBUG
-            cloudKitContainerID = "iCloud.com.tt.feelsDebug"
+            cloudKitContainerID = "iCloud.com.88oakapps.feels.debug"
             #else
-            cloudKitContainerID = "iCloud.com.tt.feels"
+            cloudKitContainerID = "iCloud.com.88oakapps.feels"
             #endif
 
             let configuration = ModelConfiguration(

Shared/Persisence/SharedModelContainer.swift

@@ -107,9 +107,9 @@ enum SharedModelContainer {
     /// CloudKit container identifier based on build configuration
     static var cloudKitContainerID: String {
         #if DEBUG
-        return "iCloud.com.tt.feelsDebug"
+        return "iCloud.com.88oakapps.feels.debug"
         #else
-        return "iCloud.com.tt.feels"
+        return "iCloud.com.88oakapps.feels"
         #endif
     }