feat: port "rename history entries" onto the runes history module

PR #1982 (merged into develop) replaced history.ts with the runes-based
historyState.svelte.ts and rewrote History.svelte, so this re-applies the
rename feature on the new architecture:

- add renameEntry(id, name) to historyState.svelte.ts (trims, no-ops on
  blank names or in loader mode, routes via the active slot)
- re-add the inline rename UI (pencil button + input, Enter/Escape/blur)
  to the rewritten History.svelte, with truncation
- port the rename unit tests to historyState.test.ts and add an e2e case

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/lib/components/History/History.svelte

@@ -10,6 +10,7 @@
   import BookmarkIcon from '~icons/material-symbols/bookmark-outline-rounded';
   import TrashAltIcon from '~icons/material-symbols/delete-outline-rounded';
   import DownloadIcon from '~icons/material-symbols/download-rounded';
+  import EditIcon from '~icons/material-symbols/edit-outline-rounded';
   import SaveIcon from '~icons/material-symbols/save-outline-rounded';
   import UndoIcon from '~icons/material-symbols/settings-backup-restore-rounded';
   import UploadIcon from '~icons/material-symbols/upload-rounded';
@@ -23,6 +24,7 @@
     clearActive,
     historyState,
     removeEntry,
+    renameEntry,
     restoreEntries,
     setMode
   } from './historyState.svelte';
@@ -48,6 +50,17 @@
     }
   });
 
+  // Inline rename state for a single entry.
+  let editingId: string | null = $state(null);
+  let editValue = $state('');
+
+  const commitRename = () => {
+    if (editingId !== null && editValue.trim()) {
+      renameEntry(editingId, editValue);
+    }
+    editingId = null;
+  };
+
   const emptyMessage = $derived(
     historyState.mode === 'auto'
       ? 'No timeline snapshots yet.\nThe Timeline is saved automatically every minute.'
@@ -147,21 +160,49 @@
       {/if}
     </div>
   {/snippet}
-  <ul class="flex h-full min-w-fit flex-col gap-2 overflow-auto p-2" id="historyList">
+  <ul class="flex h-full flex-col gap-2 overflow-auto p-2" id="historyList">
     {#if entriesWithUrl.length > 0}
       {#each entriesWithUrl as { id, state, time, name, url, type, openUrl } (id)}
         <li class="flex flex-col gap-2">
           <div class="flex items-center justify-between">
-            <div class="flex flex-col">
-              {#if url}
-                <a
-                  href={url}
-                  target="_blank"
-                  title="Open revision in new tab"
-                  class="text-blue-500 hover:underline">{name}</a>
-              {:else}
-                <span class="whitespace-nowrap">{name}</span>
-              {/if}
+            <div class="flex min-w-0 flex-1 flex-col">
+              <div class="flex min-w-0 items-center gap-1 overflow-hidden">
+                {#if url}
+                  <a
+                    href={url}
+                    target="_blank"
+                    rel="noopener"
+                    title="Open revision in new tab"
+                    class="min-w-0 truncate text-blue-500 hover:underline">{name}</a>
+                {:else if editingId === id}
+                  <input
+                    class="min-w-0 flex-1 rounded border px-1 text-sm"
+                    bind:value={editValue}
+                    aria-label="Rename entry"
+                    onkeydown={(event) => {
+                      if (event.key === 'Enter') {
+                        commitRename();
+                      } else if (event.key === 'Escape') {
+                        editingId = null;
+                      }
+                    }}
+                    onblur={commitRename} />
+                {:else}
+                  <span class="min-w-0 truncate" title={name}>{name}</span>
+                  {#if type !== 'loader'}
+                    <button
+                      type="button"
+                      class="shrink-0 opacity-50 hover:opacity-100"
+                      title="Rename"
+                      onclick={() => {
+                        editingId = id;
+                        editValue = name ?? '';
+                      }}>
+                      <EditIcon class="size-3.5" />
+                    </button>
+                  {/if}
+                {/if}
+              </div>
               <span class="text-xs whitespace-nowrap text-primary-foreground/30">
                 {new Date(time).toLocaleString()}
               </span>

src/lib/components/History/historyState.svelte.ts

@@ -139,6 +139,16 @@ export const removeEntry = (id: string): void => {
   logEvent('history', { action: 'clear', type: 'single' });
 };
 
+export const renameEntry = (id: string, name: string): void => {
+  const trimmed = name.trim();
+  const slot = slotFor(mode.value);
+  if (!trimmed || !slot) {
+    return;
+  }
+  slot.value = slot.value.map((entry) => (entry.id === id ? { ...entry, name: trimmed } : entry));
+  logEvent('history', { action: 'rename' });
+};
+
 export const clearActive = (): void => {
   const slot = slotFor(mode.value);
   if (!slot) {

src/lib/components/History/historyState.test.ts

@@ -8,6 +8,7 @@ import {
   historyState,
   injectHistoryIDs,
   removeEntry,
+  renameEntry,
   restoreEntries,
   setLoaderEntries,
   setMode,
@@ -184,6 +185,51 @@ describe('removeEntry / clearActive', () => {
   });
 });
 
+describe('renameEntry', () => {
+  it('renames an entry in the active (manual) store', () => {
+    addManualEntry(codeState('graph TD\n A-->B'));
+    setMode('manual');
+    renameEntry(historyState.entries[0].id, 'my-custom-name');
+    expect(historyState.entries[0].name).toBe('my-custom-name');
+  });
+
+  it('renames an entry in the auto store', () => {
+    addAutoEntry(codeState('graph TD\n A-->B'));
+    setMode('auto');
+    renameEntry(historyState.entries[0].id, 'auto-renamed');
+    expect(historyState.entries[0].name).toBe('auto-renamed');
+  });
+
+  it('only renames the targeted entry and trims the name', () => {
+    addManualEntry(codeState('graph TD\n A-->B'));
+    addManualEntry(codeState('graph TD\n A-->C'));
+    setMode('manual');
+    const firstName = historyState.entries[0].name;
+    const targetId = historyState.entries[1].id;
+    renameEntry(targetId, '  trimmed-name  ');
+    expect(historyState.entries[0].name).toBe(firstName);
+    expect(historyState.entries[1].name).toBe('trimmed-name');
+  });
+
+  it('ignores blank names', () => {
+    addManualEntry(codeState('graph TD\n A-->B'));
+    setMode('manual');
+    const before = historyState.entries[0].name;
+    renameEntry(historyState.entries[0].id, '   ');
+    expect(historyState.entries[0].name).toBe(before);
+  });
+
+  it('does nothing in loader mode', () => {
+    setLoaderEntries([
+      { name: 'rev', state: defaultState, time: 1, type: 'loader', url: 'http://x' }
+    ]);
+    setMode('loader');
+    const id = historyState.entries[0].id;
+    renameEntry(id, 'changed');
+    expect(historyState.entries[0].name).toBe('rev');
+  });
+});
+
 describe('setLoaderEntries', () => {
   it('replaces the in-memory revisions and assigns ids', () => {
     setLoaderEntries([

tests/history.spec.ts

@@ -144,4 +144,18 @@ test.describe('History', () => {
     await expect(page.locator('#historyList li')).toHaveCount(0);
     await expect(page.locator('#historyList')).toContainText('No saved states yet.');
   });
+
+  test('renames a saved entry inline', async ({ page }) => {
+    await openHistory(page);
+    await page.locator('#saveHistory').click();
+    await expect(page.locator('#historyList li')).toHaveCount(1);
+
+    await page.getByRole('button', { name: 'Rename' }).first().click();
+    const input = page.getByRole('textbox', { name: 'Rename entry' });
+    await input.fill('my-custom-name');
+    await input.press('Enter');
+
+    await expect(page.locator('#historyList')).toContainText('my-custom-name');
+    await expect(page.locator('#historyList li')).toHaveCount(1);
+  });
 });