fix: API key "Last used" showed date only, not time

Also removes HANDOFF.md, SECURITY_AUDIT.md, TODO.md (stale docs).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/lib/changelog.ts

@@ -1,5 +1,5 @@
 // Mirrors CHANGELOG.md at the repo root — update both together.
-export const APP_VERSION = "0.25.0";
+export const APP_VERSION = "0.25.1";
 
 export type ChangelogEntry = {
   version: string;
@@ -11,6 +11,13 @@ export type ChangelogEntry = {
 };
 
 export const CHANGELOG: ChangelogEntry[] = [
+  {
+    version: "0.25.1",
+    date: "2026-07-14 09:40",
+    fixed: [
+      "API key \"Last used\" only showed a date — now shows date and time.",
+    ],
+  },
   {
     version: "0.25.0",
     date: "2026-07-14 09:36",