AI desktop path: plain-HTML Review and Cost tabs over the Qt bridge, gate in Python

ai_sections.html pastes into the no-AI dashboard.html; ai_bridge.py adds one
ai_request slot that hands every AI contract request (incl. GET /roi) to the
review backend's dispatch(). Desktop page check reruns the web review and cost
cases plus a tampered-page gate case. Eval fixture e-pyqt-ai added.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/fixtures/e-pyqt-ai/inbox/invoice-2202.pdf

@@ -0,0 +1,2 @@
+%PDF-1.4
+% sample invoice placeholder