feat(server,app): redesign git/GitHub refresh architecture with server authority

Centralizes refresh orchestration in WorkspaceGitService and GitHubService:
server coalesces, deduplicates, and throttles git/GitHub reads; clients peek
snapshots (cold reads fall through to a one-shot fetch) and never drive
refreshes. Introduces a two-TTL model (consumer vs internal), force-emit
bypass so fingerprint-matched refreshes still propagate, notifyGitMutation
wiring at ~13 action handlers, adaptive GitHub polling based on check state,
and checkout_status_update / prStatus push-to-cache wire messages. Fixes the
stale diff-stat bug and the inverted base-branch diff direction, and flips
next-action affordances promptly after commit / PR merge.

packages/server/src/client/daemon-client.ts

@@ -945,9 +945,9 @@ export class DaemonClient {
     };
   }
 
-  on(
-    type: SessionOutboundMessage["type"],
-    handler: (message: SessionOutboundMessage) => void,
+  on<TType extends SessionOutboundMessage["type"]>(
+    type: TType,
+    handler: (message: Extract<SessionOutboundMessage, { type: TType }>) => void,
   ): () => void;
   on(handler: DaemonEventHandler): () => void;
   on(
@@ -3043,9 +3043,6 @@ export class DaemonClient {
         if (settled) {
           return;
         }
-        if (message.type !== "agent_update") {
-          return;
-        }
         if (message.payload.kind !== "upsert") {
           return;
         }