feat: window-diff-based Type Agent locating for Open Dental appointment flow

Replaces fragile whole-screen text matching with a screenshot-diff step that
finds each dialog's actual pixel bounds, then restricts every subsequent AI
locate/click to that cropped region — eliminating false matches from text
elsewhere on screen (title bars, side panels). Adds column-boundary and
row-height detection so the patient row and Exam procedure click positions
are computed geometrically instead of relying on repeated fuzzy AI guesses
for visually similar neighbors. Also adds per-run screenshot/debug-crop
backups and a structured run.log for diagnosing failed runs, plus a
cmd:move primitive on the Windows agent for pre-click confirmation crops.

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

apps/Backend/scripts/fake-windows-agent.js

@@ -29,6 +29,11 @@ socket.on("cmd:screenshot", (_payload, ack) => {
   ack({ image: FAKE_SCREENSHOT });
 });
 
+socket.on("cmd:move", ({ x, y }, ack) => {
+  console.log(`🖱️  move to (${x}, ${y}) (no click)`);
+  ack({ ok: true });
+});
+
 socket.on("cmd:click", ({ x, y }, ack) => {
   console.log(`🖱️  click at (${x}, ${y})`);
   ack({ ok: true });