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/app/src/hooks/use-checkout-status-query.ts

@@ -1,13 +1,7 @@
-import { useQuery } from "@tanstack/react-query";
-import { useEffect, useMemo, useRef } from "react";
-import { useIsCompactFormFactor } from "@/constants/layout";
-import { usePanelStore } from "@/stores/panel-store";
+import { type QueryClient, useQuery, useQueryClient } from "@tanstack/react-query";
+import { useEffect } from "react";
 import { useHostRuntimeClient, useHostRuntimeIsConnected } from "@/runtime/host-runtime";
 import type { CheckoutStatusResponse } from "@server/shared/messages";
-import {
-  checkoutStatusRevalidationKey,
-  nextCheckoutStatusRefetchDecision,
-} from "./checkout-status-revalidation";
 
 export const CHECKOUT_STATUS_STALE_TIME = 15_000;
 
@@ -22,22 +16,56 @@ interface UseCheckoutStatusQueryOptions {
 
 export type CheckoutStatusPayload = CheckoutStatusResponse["payload"];
 
+interface CheckoutStatusClient {
+  getCheckoutStatus: (cwd: string) => Promise<CheckoutStatusPayload>;
+}
+
 function fetchCheckoutStatus(
-  client: { getCheckoutStatus: (cwd: string) => Promise<CheckoutStatusPayload> },
+  client: CheckoutStatusClient,
   cwd: string,
 ): Promise<CheckoutStatusPayload> {
   return client.getCheckoutStatus(cwd);
 }
 
+async function peekOrFetchSnapshot({
+  queryClient,
+  client,
+  serverId,
+  cwd,
+}: {
+  queryClient: QueryClient;
+  client: CheckoutStatusClient;
+  serverId: string;
+  cwd: string;
+}): Promise<CheckoutStatusPayload> {
+  const queryKey = checkoutStatusQueryKey(serverId, cwd);
+  const cached = queryClient.getQueryData<CheckoutStatusPayload>(queryKey);
+  if (cached) {
+    return cached;
+  }
+
+  const snapshot = await fetchCheckoutStatus(client, cwd);
+  queryClient.setQueryData(queryKey, snapshot);
+  return snapshot;
+}
+
 export function useCheckoutStatusQuery({ serverId, cwd }: UseCheckoutStatusQueryOptions) {
+  const queryClient = useQueryClient();
   const client = useHostRuntimeClient(serverId);
   const isConnected = useHostRuntimeIsConnected(serverId);
-  const isMobile = useIsCompactFormFactor();
-  const mobileView = usePanelStore((state) => state.mobileView);
-  const desktopFileExplorerOpen = usePanelStore((state) => state.desktop.fileExplorerOpen);
-  const explorerTab = usePanelStore((state) => state.explorerTab);
-  const isOpen = isMobile ? mobileView === "file-explorer" : desktopFileExplorerOpen;
-  const shouldPoll = isOpen && explorerTab === "changes";
+
+  useEffect(() => {
+    if (!client || !isConnected || !cwd) {
+      return;
+    }
+
+    return client.on("checkout_status_update", (message) => {
+      if (message.payload.cwd !== cwd) {
+        return;
+      }
+      queryClient.setQueryData(checkoutStatusQueryKey(serverId, cwd), message.payload);
+    });
+  }, [client, isConnected, cwd, queryClient, serverId]);
 
   const query = useQuery({
     queryKey: checkoutStatusQueryKey(serverId, cwd),
@@ -45,42 +73,21 @@ export function useCheckoutStatusQuery({ serverId, cwd }: UseCheckoutStatusQuery
       if (!client) {
         throw new Error("Daemon client not available");
       }
-      return await fetchCheckoutStatus(client, cwd);
+      return await peekOrFetchSnapshot({ queryClient, client, serverId, cwd });
     },
     enabled: !!client && isConnected && !!cwd,
-    staleTime: CHECKOUT_STATUS_STALE_TIME,
-    refetchInterval: (query) => {
-      if (!shouldPoll) return false;
-      const data = query.state.data as CheckoutStatusPayload | undefined;
-      return data?.isGit ? 10_000 : false;
-    },
-    refetchIntervalInBackground: shouldPoll,
-    refetchOnMount: "always",
+    staleTime: Infinity,
+    refetchOnMount: false,
+    refetchOnReconnect: false,
+    refetchOnWindowFocus: false,
   });
 
-  // Revalidate when sidebar is open with "changes" tab active.
-  const revalidationKey = useMemo(
-    () => checkoutStatusRevalidationKey({ serverId, cwd, isOpen, explorerTab }),
-    [serverId, cwd, isOpen, explorerTab],
-  );
-  const lastRevalidationKey = useRef<string | null>(null);
-  useEffect(() => {
-    const decision = nextCheckoutStatusRefetchDecision(
-      lastRevalidationKey.current,
-      revalidationKey,
-    );
-    lastRevalidationKey.current = decision.nextSeenKey;
-    if (!decision.shouldRefetch) return;
-    void query.refetch();
-  }, [revalidationKey, query.refetch]);
-
   return {
     status: query.data ?? null,
     isLoading: query.isLoading,
     isFetching: query.isFetching,
     isError: query.isError,
     error: query.error,
-    refresh: query.refetch,
   };
 }