feat(git): add commit-note support and previews in history

This change adds Git notes support to the history UI.
Commits now carry a has_note flag which triggers a note indicator.
Notes can be previewed on hover and loaded on demand,
then the history can be refreshed after edits.

- Adds has_note support on commits and parses from logs.
- Renders a note indicator in history rows with a hover preview.
- Triggers history refresh after note-related actions.

src/lib/components/HistoryPanel.svelte

@@ -80,6 +80,7 @@
     onCherryPickCommit: (commit: GitCommit) => void;
     onRevertCommit: (commit: GitCommit) => void;
     onOpenCommitNote: (commit: GitCommit) => void;
+    onLoadCommitNote: (commit: GitCommit) => Promise<string | null>;
     onSelectCommit: (commit: GitCommit) => void;
   }
 
@@ -108,6 +109,7 @@
     onCherryPickCommit = () => {},
     onRevertCommit = () => {},
     onOpenCommitNote = () => {},
+    onLoadCommitNote = async () => null,
     onSelectCommit = () => {},
   }: Props = $props();
 
@@ -120,6 +122,16 @@
   let contextCommit = $state<GitCommit | null>(null);
   let contextMenuX = $state(0);
   let contextMenuY = $state(0);
+  let notePreviews = $state<Record<string, string>>({});
+  let notePreviewLoading = $state<Set<string>>(new Set());
+  let notePreviewErrors = $state<Set<string>>(new Set());
+
+  $effect(() => {
+    repositoryKey;
+    notePreviews = {};
+    notePreviewLoading = new Set();
+    notePreviewErrors = new Set();
+  });
 
   function observeHistoryEnd(node: HTMLElement) {
     const root = node.closest<HTMLElement>(".history-list");
@@ -503,6 +515,34 @@
     await onOpenCommitNote(commit);
   }
 
+  async function loadCommitNotePreview(commit: GitCommit) {
+    if (!commit.has_note || notePreviewLoading.has(commit.hash)) return;
+
+    const loading = new Set(notePreviewLoading);
+    loading.add(commit.hash);
+    notePreviewLoading = loading;
+
+    const errors = new Set(notePreviewErrors);
+    errors.delete(commit.hash);
+    notePreviewErrors = errors;
+
+    try {
+      const note = await onLoadCommitNote(commit);
+      notePreviews = {
+        ...notePreviews,
+        [commit.hash]: note?.trim() || "This Git note is empty.",
+      };
+    } catch {
+      const nextErrors = new Set(notePreviewErrors);
+      nextErrors.add(commit.hash);
+      notePreviewErrors = nextErrors;
+    } finally {
+      const nextLoading = new Set(notePreviewLoading);
+      nextLoading.delete(commit.hash);
+      notePreviewLoading = nextLoading;
+    }
+  }
+
   function handleWindowKeydown(event: KeyboardEvent) {
     if (event.key !== "Escape") return;
     closeCommitContextMenu();
@@ -792,6 +832,7 @@
         <article
           class="commit-row graph-row"
           class:selected={selectedCommitHash === item.hash}
+          class:has-note={item.has_note}
           data-commit-hash={item.hash}
           class:graph-ahead-row={rowSyncClass === "ahead"}
           class:graph-behind-row={rowSyncClass === "behind"}
@@ -852,6 +893,9 @@
             class:has-branch-ref={Boolean(refSummary.primaryBranch)}
             style={`--ref-lane-color:${row?.dotColor ?? GRAPH_COLORS[0]}`}
           >
+            {#if item.has_note}
+              <span class="commit-note-rail" aria-hidden="true"></span>
+            {/if}
             {#if refSummary.primaryBranch || refSummary.primaryTag || refSummary.overflowCount > 0}
               <div class="commit-ref-area">
                 <div class="commit-ref-strip" aria-label="Commit references">
@@ -966,6 +1010,43 @@
                 <div class="commit-meta-line">
                   <span class="commit-hash">{item.short_hash}</span>
                   <span class="commit-author" title={item.author_email}>{item.author_name}</span>
+                  {#if item.has_note}
+                    <span class="commit-note-indicator">
+                      <button
+                        class="commit-note-presence"
+                        type="button"
+                        onpointerenter={() => void loadCommitNotePreview(item)}
+                        onfocus={() => void loadCommitNotePreview(item)}
+                        onclick={() => openCommitNote(item)}
+                        disabled={isBusy}
+                        aria-label={`Open Git note for ${item.short_hash}`}
+                        aria-describedby={`commit-note-preview-${item.hash}`}
+                      >
+                        <StickyNote size={11} aria-hidden="true" />
+                        <span>Note</span>
+                      </button>
+                      <span
+                        class="commit-note-tooltip"
+                        id={`commit-note-preview-${item.hash}`}
+                        role="tooltip"
+                      >
+                        <span class="commit-note-tooltip-head">
+                          <StickyNote size={12} aria-hidden="true" />
+                          Git Note
+                          <small>Click to open</small>
+                        </span>
+                        <span class="commit-note-tooltip-body">
+                          {#if notePreviewLoading.has(item.hash)}
+                            Loading note…
+                          {:else if notePreviewErrors.has(item.hash)}
+                            Note could not be loaded.
+                          {:else}
+                            {notePreviews[item.hash] ?? "Hover to load the note."}
+                          {/if}
+                        </span>
+                      </span>
+                    </span>
+                  {/if}
                 </div>
               </div>
             </div>
@@ -1008,16 +1089,18 @@
             <div class="commit-actions">
               <time class="commit-time" datetime={item.date}>{formatCommitDate(item.date)}</time>
               <div class="commit-action-buttons">
-                <button
-                  class="commit-menu-button commit-note-button"
-                  type="button"
-                  onclick={() => openCommitNote(item)}
-                  disabled={isBusy}
-                  title={`Open internal note for ${item.short_hash}`}
-                  aria-label={`Open internal note for ${item.short_hash}`}
-                >
-                  <StickyNote size={14} aria-hidden="true" />
-                </button>
+                {#if !item.has_note}
+                  <button
+                    class="commit-menu-button commit-note-button"
+                    type="button"
+                    onclick={() => openCommitNote(item)}
+                    disabled={isBusy}
+                    title={`Add a Git note to ${item.short_hash}`}
+                    aria-label={`Add a Git note to ${item.short_hash}`}
+                  >
+                    <StickyNote size={14} aria-hidden="true" />
+                  </button>
+                {/if}
                 <button
                   class="commit-menu-button"
                   type="button"

src/lib/types.ts

@@ -178,6 +178,7 @@ export interface GitCommit {
   refs: string[];
   parents: string[];
   files: GitCommitFile[];
+  has_note: boolean;
 }
 
 export interface GitCommitFile {