Polish: draft autosave, history refresh, outdated footer, more

Bug fixes / UX

- Footer: the privacy line still claimed 'generation runs in your
  browser'. Now correctly says the generation runs on the server and
  the key never reaches the browser.

- History panel: when the panel was open while a new generation
  completed, the new entry didn't appear until the user closed and
  re-opened the panel. The history module now dispatches a custom
  'melodymuse-history-updated' event on every write; the panel
  listens and re-reads. removeFromHistory/clearHistory emit too.
  writeAll is also now try/catch'd against quota errors.

- Auto-save the input form: the input is persisted to localStorage
  ('melodymuse-draft', debounced 400ms) so a refresh doesn't wipe
  what the user was typing. The initial state hydrates from the
  draft on mount.

- Cmd/Ctrl+Enter now works in the Music style field as well as
  the idea field — shared onKeyDown handler, propagated through the
  StyleField sub-component.

- Full regen ('Generate' / 'Regenerate All') now clears the previous
  assets before kicking off the new request, so the skeleton state
  shows during the round-trip instead of stale cards with a spinner
  on top. Per-section regen still leaves the other cards intact.

- Settings → Local data: the in-progress draft is now listed
  alongside history and theme, and has its own 'Clear in-progress
  draft' button. The 'Clear all local data' button clears it too.

src/components/HistoryPanel.tsx

@@ -1,13 +1,14 @@
-import { useEffect, useState } from 'react';
-import { Clock, History, Trash2, X } from 'lucide-react';
+import { useEffect, useState } from "react";
+import { Clock, History, Trash2, X } from "lucide-react";
 import {
   clearHistory,
   formatRelative,
+  HISTORY_UPDATED_EVENT,
   loadHistory,
   removeFromHistory,
   type HistoryEntry,
-} from '../lib/history';
-import type { InputValues } from '../lib/types';
+} from "../lib/history";
+import type { InputValues } from "../lib/types";
 
 interface HistoryPanelProps {
   onLoad: (entry: HistoryEntry) => void;
@@ -17,13 +18,23 @@ export function HistoryPanel({ onLoad }: HistoryPanelProps) {
   const [open, setOpen] = useState(false);
   const [entries, setEntries] = useState<HistoryEntry[]>([]);
 
-  // Refresh the list whenever the panel is opened, so newly-saved generations
-  // appear without needing a full page refresh.
+  // Refresh the list whenever the panel is opened.
   useEffect(() => {
     if (!open) return;
     setEntries(loadHistory());
   }, [open]);
 
+  // And whenever the history is updated from elsewhere in the app (after a
+  // successful generation, or a delete/clear from a different panel).
+  useEffect(() => {
+    const handler = () => {
+      if (!open) return;
+      setEntries(loadHistory());
+    };
+    window.addEventListener(HISTORY_UPDATED_EVENT, handler);
+    return () => window.removeEventListener(HISTORY_UPDATED_EVENT, handler);
+  }, [open]);
+
   if (entries.length === 0 && !open) {
     return null;
   }
@@ -43,7 +54,7 @@ export function HistoryPanel({ onLoad }: HistoryPanelProps) {
             <span className="text-xs text-fg-muted">({entries.length})</span>
           )}
         </span>
-        <span className="text-xs text-fg-muted">{open ? 'Hide' : 'Show'}</span>
+        <span className="text-xs text-fg-muted">{open ? "Hide" : "Show"}</span>
       </button>
 
       {open && (
@@ -130,6 +141,6 @@ function HistoryRow({
 function summarizeInput(v: InputValues): string {
   const idea = v.idea.trim();
   const max = 90;
-  if (idea.length <= max) return idea || '(no idea text)';
-  return idea.slice(0, max - 1) + '…';
+  if (idea.length <= max) return idea || "(no idea text)";
+  return idea.slice(0, max - 1) + "…";
 }