Polish footer menu, Notes spacing, and Appointments add flow

- User menu: rename "Quick nav" to "Search"; add spacing to the clinic
  submenu so it no longer touches the parent menu (sideOffset).
- Notes: lay the list, title, toolbar, and writing area out as separate
  rounded panels with gaps so they're no longer stuck together.
- Sidebar: shorten the "Appointments & Schedule" label to "Appointments".
- Appointments: replace the oversized patient form with a compact
  "New appointment" dialog — pick a patient via quick search by name/file
  number, set time/type/provider; the entry is added to today's schedule.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/lib/i18n/locales/en/translation.json

@@ -47,7 +47,7 @@
   "nav": {
     "newChat": "New chat",
     "patients": "Patients",
-    "appointments": "Appointments & Schedule",
+    "appointments": "Appointments",
     "analysis": "Analysis",
     "notes": "Notes",
     "settings": "Settings",