Add ListApps RPC for querying installed applications (#75)

- Add AppInfo message with name and version fields
- Add ListAppsRequest and ListAppsResponse messages
- Add ListApps RPC to SynapseDevice service

This enables clients to query the list of installed applications
on a device, complementing the existing DeployApp RPC.

Author: maxhodak

api/app.proto

@@ -53,3 +53,19 @@ message AppPerformanceSummary {
   uint64 timestamp_ns = 1;
   repeated FunctionProfile function_profiles = 2;
 }
+
+// Information about an installed application
+message AppInfo {
+  // Application name (e.g., "synapse-example-app")
+  string name = 1;
+
+  // Installed version
+  string version = 2;
+}
+
+message ListAppsRequest {
+}
+
+message ListAppsResponse {
+  repeated AppInfo apps = 1;
+}

api/synapse.proto

@@ -20,6 +20,7 @@ service SynapseDevice {
   rpc StreamQuery(StreamQueryRequest) returns (stream StreamQueryResponse) {}
 
   rpc DeployApp(stream AppPackageChunk) returns (stream AppDeployResponse) {}
+  rpc ListApps(ListAppsRequest) returns (ListAppsResponse) {}
 
   rpc ListFiles(google.protobuf.Empty) returns (ListFilesResponse) {}
   rpc WriteFile(WriteFileRequest) returns (WriteFileResponse) {}