fix(windows): repair browser startup and computer focus guidance

[killswitch-GUI]

Windows browser startup could crash before opening a tab when a configured application home produced a temporary engine profile beyond Chromium's Windows path limit. Allocate that temporary state in a short, private directory under the token-derived Windows user profile, retaining the instance binding and existing native cleanup ownership. Disable Chrome's file-logging destination outside explicit startup diagnostics.

Disconnecting the browser viewer repeatedly reissued native hide/focus-loss calls during subsequent agent operations. Apply terminal viewer revocation once while keeping its admission fence permanently closed. Regression tests cover duplicate notifications, repeated event-loop passes, denied viewer commands and closing acknowledgements.

Computer observations can read a background window without activating it. When the selected window is in the background, the bundled skill, tool descriptions and stale-observation guidance now direct the agent to focus it and obtain a fresh observation before input. Existing foreground, identity, observation and permission guards are unchanged. The Windows CI runner keeps raw startup fixtures short and applies long managed ancestry only to the runtime factory regression.

Validation:

• Clean 02076cfd source Release-host acceptance passed all twelve browser checks, including all four keyboard-navigation cases, long managed ancestry, a short private engine profile, no file logs, real input, frames, transfers, tabs and acknowledged native cleanup (17.47 seconds).

• Clean 02076cfd, ordinary-user native Computer Use acceptance passed, including two fresh background-click rejections followed by explicit focus and successful input, modal and contention guards, cancellation, balanced drag and cleanup (15.84 seconds).

• The new terminal-revocation regression failed against the prior implementation (14 native revocations instead of one). All seven linked presentation tests and strict Release Clippy passed after the fix.

• Four Windows token-profile tests, the Runtime path-budget test, focused computer guidance/packaging tests, and strict feature Clippy passed. The existing Windows native CI lane now exercises the Release host.

• cargo xtask check rust passed in full on the clean commit, including workspace tests, documentation tests and strict fuzz Clippy.

• cargo xtask pr --base origin/main passed workflow contracts and its complete Rust checks, then stopped at the explicit Windows limitation: SDK generation requires the repository's POSIX generator scripts. SDK, Desktop, documentation and dependency checks were not reached locally; required hosted checks remain mandatory.

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[chatgpt-codex-connector]

Codex Review Summary

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-19T22:35:41.216551Z	d714d59	PR opened

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