add keyboard tracking and app-qualified smart titles

**Keyboard hook (Windows)**
- Extends the existing C# WH_MOUSE_LL process to also install
  WH_KEYBOARD_LL alongside it (keyboard hook is optional — failure
  does not break mouse capture).
- Emits CHAR <code> <ts> for printable keystrokes, KEY <name> <ts>
  for modifier combos (Ctrl+T) and special keys (Backspace, Enter).

**Text accumulation in capture session**
- CaptureService tracks _keyBuffer (typed chars since last step) and
  _lastShortcut (last modifier combo) using the new onKeyboardEvent()
  method.
- snapshotKeyContext() is called at enqueueClickCapture time so each
  step's clickMeta.keyContext carries { recentTyped, recentShortcut }.
- Buffer resets after each snapshot; stale input (>8s gap) is dropped.

**UIAutomation element value**
- collectWindowsWindowContext now reads ValuePattern.Current.Value
  from the clicked element — giving us what's actually typed in a
  search box or text field without needing the keyboard buffer.

**Smart title generation (core/text-intel.js)**
- Priority chain: keyboard shortcut → element value → typed text
  → OCR → element label → page title → app name.
- SHORTCUT_TITLES maps 50+ common shortcuts (Ctrl+T, Ctrl+S, F5 …)
  to natural language descriptions: "Open new tab", "Save", etc.
- qualifyTitleWithApp() appends "in Chrome / VS Code / Terminal / …"
  to every title when the app is known: "Click Save in VS Code",
  "Search for oracle in Chrome", "Open new tab in Chrome".
- APP_DISPLAY_NAMES covers browsers, editors, terminals, office apps.

Six new unit tests cover shortcuts, typed-text search, element value,
and app-qualified OCR titles. Capture test updated for keyContext.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

tests/unit/capture.test.js

@@ -375,7 +375,7 @@ test('queued click captures preserve the original event time and button', async
   assert.deepEqual(seen, [{
     trigger: 'click',
     clickPos: { x: 7, y: 8 },
-    clickMeta: { at: 1770000000456, button: 'left' },
+    clickMeta: { at: 1770000000456, button: 'left', keyContext: { recentTyped: '', recentShortcut: '' } },
   }]);
 });