Add missing FCM support classes

- ClippyResponseBus: SharedFlow event bus for FCM + sync responses
- ResponseDedup: SHA-256 dedup with sliding window
- Updated ClippyFCMService and FCMTokenManager to use MatrixRestClient
- Added putAccountData() to MatrixRestClient for FCM token storage

Co-authored-by: Spirit <spirit@hobbs.farm>

app/src/main/java/farm/hobbs/clippyauto/matrix/MatrixRestClient.kt

@@ -164,6 +164,27 @@ class MatrixRestClient(
         }
     }
 
+
+    /**
+     * Store account data in Matrix.
+     * Used for FCM token registration so n8n can read it.
+     */
+    suspend fun putAccountData(userId: String, type: String, data: Map<String, String>): Boolean {
+        return try {
+            val response = client.put("$homeserverUrl/_matrix/client/v3/user/$userId/account_data/$type") {
+                header("Authorization", "Bearer $accessToken")
+                contentType(ContentType.Application.Json)
+                setBody(buildJsonObject {
+                    data.forEach { (key, value) -> put(key, value) }
+                }.toString())
+            }
+            response.status.isSuccess()
+        } catch (e: Exception) {
+            Log.e("MatrixREST", "putAccountData failed", e)
+            false
+        }
+    }
+
     fun shutdown() {
         httpClient.close()
     }