feat: add long-press contextual actions on post cards

Long press any post card to open a context menu with state-aware actions:
- Copy text (all states)
- ERROR: Retry now, Edit & retry, View error message
- QUEUE: Edit, Reschedule (native DateTimePicker → PUT /posts/:id)
- PUBLISHED: Repost
- DRAFT: Edit & schedule

Compose screen now accepts prefillContent/prefillIntegrationIds router
params to pre-fill content and channel selection when editing or reposting.
Adds expo-clipboard for clipboard support.

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

pnpm-lock.yaml

@@ -398,6 +398,9 @@ importers:
       axios:
         specifier: ^1.15.2
         version: 1.15.2
+      expo-clipboard:
+        specifier: ~8.0.8
+        version: 8.0.8(expo@54.0.34)(react-native@0.81.5(@babel/core@7.29.0)(@types/react@19.1.17)(react@19.1.0))(react@19.1.0)
       expo-notifications:
         specifier: ~0.32.17
         version: 0.32.17(expo@54.0.34)(react-native@0.81.5(@babel/core@7.29.0)(@types/react@19.1.17)(react@19.1.0))(react@19.1.0)(typescript@5.9.3)
@@ -3384,6 +3387,13 @@ packages:
       react: '*'
       react-native: '*'
 
+  expo-clipboard@8.0.8:
+    resolution: {integrity: sha512-VKoBkHIpZZDJTB0jRO4/PZskHdMNOEz3P/41tmM6fDuODMpqhvyWK053X0ebspkxiawJX9lX33JXHBCvVsTTOA==}
+    peerDependencies:
+      expo: '*'
+      react: '*'
+      react-native: '*'
+
   expo-constants@18.0.13:
     resolution: {integrity: sha512-FnZn12E1dRYKDHlAdIyNFhBurKTS3F9CrfrBDJI5m3D7U17KBHMQ6JEfYlSj7LG7t+Ulr+IKaj58L1k5gBwTcQ==}
     peerDependencies:
@@ -9386,6 +9396,12 @@ snapshots:
       react: 19.1.0
       react-native: 0.81.5(@babel/core@7.29.0)(@types/react@19.1.17)(react@19.1.0)
 
+  expo-clipboard@8.0.8(expo@54.0.34)(react-native@0.81.5(@babel/core@7.29.0)(@types/react@19.1.17)(react@19.1.0))(react@19.1.0):
+    dependencies:
+      expo: 54.0.34(@babel/core@7.29.0)(@expo/metro-runtime@6.1.2)(expo-router@6.0.23)(react-native@0.81.5(@babel/core@7.29.0)(@types/react@19.1.17)(react@19.1.0))(react@19.1.0)(typescript@5.9.3)
+      react: 19.1.0
+      react-native: 0.81.5(@babel/core@7.29.0)(@types/react@19.1.17)(react@19.1.0)
+
   expo-constants@18.0.13(expo@54.0.34)(react-native@0.81.5(@babel/core@7.29.0)(@types/react@19.1.17)(react@19.1.0)):
     dependencies:
       '@expo/config': 12.0.13