feat(app): add background commit notes fetch and refresh logic

This change adds a background path for fetching commit notes per repo
and a shared cache to avoid duplicate work. When notes are fetched
and the active repo is visible, history is refreshed to reflect
notes without blocking user actions.

- Adds per-path backgroundCommitNotesFetches cache to debounce fetches
- Integrates note fetch into the background tick and refresh flow
- Handles credential errors and shutdown gracefully during fetches

src/App.svelte

@@ -427,6 +427,7 @@
   let backgroundFetchTimer: ReturnType<typeof setInterval> | undefined;
   let backgroundRepoStatusTimer: ReturnType<typeof setInterval> | undefined;
   let backgroundFetchInFlight = false;
+  const backgroundCommitNotesFetches = new Map<string, Promise<boolean>>();
   let backgroundRepoStatusInFlight = false;
   let backgroundRepoStatusIndex = 0;
   let appShuttingDown = false;
@@ -672,6 +673,15 @@
             // Keep the cached tab data if this repo is unavailable at startup.
           }
         }
+
+        const notesFetched = await backgroundFetchCommitNotes(path);
+        if (notesFetched && sameRepoPath(path, activeRepoPath)) {
+          try {
+            await refreshCommitHistory(path);
+          } catch {
+            // The active repository may still be opening; its own background pass retries.
+          }
+        }
       }
     } finally {
       backgroundFetchInFlight = false;
@@ -717,18 +727,91 @@
   // ahead/behind (and the taskbar badge) stay accurate without the user pulling manually.
   // Errors are swallowed here — auth/network failures surface via the manual Fetch/Pull/
   // Push buttons instead, not as a background popup.
+  function preferredNotesRemote(remotes: GitRemote[]): GitRemote | undefined {
+    return remotes.find((remote) => remote.name === selectedRemote)
+      ?? remotes.find((remote) => remote.name === "origin")
+      ?? remotes[0];
+  }
+
+  async function backgroundFetchCommitNotesCore(path: string): Promise<boolean> {
+    if (appShuttingDown || !autoRefreshEnabled || !path) return false;
+    if (commitNoteTarget && sameRepoPath(path, commitNoteRepoPath)) return false;
+
+    let credentialKey: string | null = null;
+    try {
+      const remote = preferredNotesRemote(await listRemotes(path));
+      if (!remote) return false;
+
+      credentialKey = orgKeyFromUrl(remote.fetch_url);
+      if (credentialKey && rejectedCredentialKeys.has(credentialKey)) return false;
+      const credential = await loadStoredCredential(credentialKey);
+      if (/^https?:\/\//i.test(remote.fetch_url) && !credential) return false;
+      await fetchCommitNotes(path, remote.name, credential?.username, credential?.password);
+      if (credentialKey) rejectedCredentialKeys.delete(credentialKey);
+      trackEvent("commit_notes_background_fetched");
+      return true;
+    } catch (error) {
+      if (credentialKey && isAuthError(errorToMessage(error))) {
+        rejectedCredentialKeys.add(credentialKey);
+      }
+      if (import.meta.env.DEV) console.info("[Gitty notes] Background fetch skipped", errorToMessage(error));
+      return false;
+    }
+  }
+
+  function backgroundFetchCommitNotes(path: string): Promise<boolean> {
+    const key = repoKey(path);
+    const current = backgroundCommitNotesFetches.get(key);
+    if (current) return current;
+
+    const request = backgroundFetchCommitNotesCore(path).finally(() => {
+      backgroundCommitNotesFetches.delete(key);
+    });
+    backgroundCommitNotesFetches.set(key, request);
+    return request;
+  }
+
+  async function waitForBackgroundCommitNotes(path: string) {
+    await backgroundCommitNotesFetches.get(repoKey(path));
+  }
+
+  async function backgroundFetchCommitNotesAndRefresh(path: string) {
+    if (!await backgroundFetchCommitNotes(path)) return;
+    if (!sameRepoPath(path, activeRepoPath)) return;
+    try {
+      await refreshCommitHistory(path);
+    } catch {
+      // Repository changes can invalidate this best-effort background refresh.
+    }
+  }
+
   async function backgroundFetchTick() {
     if (appShuttingDown || !autoRefreshEnabled) return;
 
     if (activeView === "repository" && activeRepoPath && !backgroundFetchInFlight
       && !isBusy && Date.now() - lastRepoSwitchAt >= BACKGROUND_FETCH_AFTER_SWITCH_GRACE_MS) {
+      const path = activeRepoPath;
       backgroundFetchInFlight = true;
       try {
-        await fetchRemote(activeRepoPath);
-        applyStatus(await getStatus(activeRepoPath));
-        await refreshRefsAndCommitGraph(activeRepoPath);
+        let refsFetched = false;
+        try {
+          await fetchRemote(path);
+          refsFetched = true;
         } catch {
-        // ignore — see comment above
+          // Manual Fetch/Pull surfaces remote errors; background work stays silent.
+        }
+
+        const notesFetched = await backgroundFetchCommitNotes(path);
+        if (sameRepoPath(path, activeRepoPath)) {
+          if (refsFetched) {
+            applyStatus(await getStatus(path));
+            await refreshRefsAndCommitGraph(path);
+          } else if (notesFetched) {
+            await refreshCommitHistory(path);
+          }
+        }
+      } catch {
+        // ignore transient refresh failures
       } finally {
         backgroundFetchInFlight = false;
       }
@@ -741,15 +824,27 @@
     if (appShuttingDown || !autoRefreshEnabled || !path || backgroundFetchInFlight) return;
 
     backgroundFetchInFlight = true;
+    try {
+      let refsFetched = false;
       try {
         await fetchRemote(path);
+        refsFetched = true;
+      } catch {
+        // Manual Fetch/Pull surfaces remote errors; background work stays silent.
+      }
+
+      const notesFetched = await backgroundFetchCommitNotes(path);
+      if (refsFetched) {
         const nextStatus = await getStatus(path);
         if (sameRepoPath(path, activeRepoPath)) {
           applyStatus(nextStatus);
           await refreshRefsAndCommitGraph(path);
         } else updateRepoManagementStatus(path, nextStatus);
+      } else if (notesFetched && sameRepoPath(path, activeRepoPath)) {
+        await refreshCommitHistory(path);
+      }
     } catch {
-      // ignore; manual Fetch/Pull surfaces auth or network problems
+      // ignore transient refresh failures
     } finally {
       backgroundFetchInFlight = false;
     }
@@ -2180,7 +2275,8 @@
         changed_files: bundle.status.files.length,
         has_upstream: bundle.status.upstream ? 1 : 0,
       });
-      void backgroundFetchRepo(activeRepoPath);
+      if (backgroundFetchInFlight) void backgroundFetchCommitNotesAndRefresh(activeRepoPath);
+      else void backgroundFetchRepo(activeRepoPath);
     });
   }
 
@@ -3011,6 +3107,7 @@
     commitNoteError = "";
     commitNoteStatus = "";
     try {
+      await waitForBackgroundCommitNotes(repo);
       await setCommitNote(repo, commit.hash, note);
       commitNoteText = note;
       commits = commits.map((item) => item.hash === commit.hash ? { ...item, has_note: true } : item);
@@ -3033,6 +3130,7 @@
     commitNoteError = "";
     commitNoteStatus = "";
     try {
+      await waitForBackgroundCommitNotes(repo);
       await deleteCommitNote(repo, commit.hash);
       commitNoteText = "";
       commits = commits.map((item) => item.hash === commit.hash ? { ...item, has_note: false } : item);
@@ -3068,6 +3166,7 @@
     commitNoteError = "";
     commitNoteStatus = "";
     try {
+      await waitForBackgroundCommitNotes(repo);
       const credential = await storedCredentialForNoteRemote(remote, direction);
       if (direction === "fetch") {
         await fetchCommitNotes(repo, remote, credential?.username, credential?.password);