fix: add shared model sources to TabataGoWidget target

Widget extension references WorkoutPhase, WorkoutActivityAttributes,
TogglePauseIntent (WorkoutLiveActivity) and MusicActivityAttributes
(MusicLiveActivity) but cannot import parent app module. Shared source
files must be compiled in both targets, following existing pattern
of WatchConnectivityTypes.swift shared between iOS/watch.

tabatago-swift/project.yml

@@ -38,6 +38,8 @@ targets:
       - path: TabataGo
         excludes:
           - "**/.DS_Store"
+      - path: TabataGo/Models/WorkoutActivityAttributes.swift
+      - path: TabataGo/Models/MusicActivityAttributes.swift
     resources:
       - path: TabataGo/Resources
         excludes:
@@ -98,6 +100,8 @@ targets:
       - path: TabataGoWatch
         excludes:
           - "**/.DS_Store"
+      - path: TabataGo/Models/WorkoutActivityAttributes.swift
+      - path: TabataGo/Models/MusicActivityAttributes.swift
           - "Resources/Info.plist"
           - "Complications/**"
       # Shared protocol types — referenced by both targets
@@ -144,6 +148,8 @@ targets:
       - path: TabataGoWatch/Complications
         excludes:
           - "**/.DS_Store"
+      - path: TabataGo/Models/WorkoutActivityAttributes.swift
+      - path: TabataGo/Models/MusicActivityAttributes.swift
     info:
       path: TabataGoWatch/Complications/Info.plist
       properties:
@@ -166,6 +172,8 @@ targets:
       - path: TabataGoWidget
         excludes:
           - "**/.DS_Store"
+      - path: TabataGo/Models/WorkoutActivityAttributes.swift
+      - path: TabataGo/Models/MusicActivityAttributes.swift
     info:
       path: TabataGoWidget/Info.plist
       properties: