fix(driver): require daemon-backed calls and stabilize E2E

[f-trycua]

Summary

• require every cua-driver call and MCP dispatch to cross the daemon transport; the in-process daemonless call path is removed
• evaluate permission policies at daemon startup and enforce them at the shared dispatch boundary
• migrate protocol and E2E coverage to the daemon-backed testkit
• repair the Linux, Wayland, Windows, macOS, and standalone-browser regressions exposed by the complete post-merge matrix

Post-merge regressions fixed

• daemon-backed element-token and capture-scope behavior, including pre-turn rejection
• Wayland/WebKit and Chromium coordinate handling, compositor CDP/browser binding, and pointer/keyboard/frame protocol behavior
• compositor preservation of a background sentinel's focus and PID-only recording fallback
• Linux Edge's remote-debugging consent flow when an otherwise successful AT-SPI action is inert
• macOS and Windows foreground-sentinel setup, including a bounded retry for startup/activation races

Validation

Final candidate: f48ac5e9b3c786fb6b78e66dc6c817dea87498d6

• all ordinary PR checks pass (Linux/Windows compile and unit checks, rustfmt on all hosts, Nix policy/package/compositor jobs, docs/links, SPDX, metadata, and fleet guard)
• Linux X11 E2E: success
• Linux Sway E2E: success
• Linux cua-compositor E2E: success
• Windows interactive E2E: success
• standalone browsers on Linux and Windows: success
• macOS Lume core matrix: 148/148 passed (140 delivered, 8 policy refusals, 0 failed/skipped)
• macOS Lume standalone-browser matrix: 15/15 passed (13 delivered, 2 policy refusals, 0 failed/skipped)
• local: cargo test -p cua-driver-testkit, cargo fmt --all -- --check, and git diff --check

The macOS artifacts record the exact requested/source SHA, executable identity, signature, version, and per-case results.

This is the post-merge repair for #2337.