fix(browser): unify PATH fallbacks for Termux and Homebrew

[gut-puncture]

Summary

• centralize browser PATH fallback assembly so CLI discovery and subprocess execution use the same logic
• add Termux fallback directories alongside the existing Homebrew/system defaults so npx, node, and grun remain discoverable on Android
• extend the existing browser PATH tests with Termux regressions while preserving the Homebrew coverage

Fixes #5845.

Testing

• source venv/bin/activate && pytest tests/tools/test_browser_homebrew_paths.py

[teknium1]

Thanks for the contribution @gut-puncture! This fix has already landed on main.

Automated hermes-sweeper review

The exact changes you proposed — Termux PATH fallbacks in _SANE_PATH_DIRS, the _browser_candidate_path_dirs() and _merge_browser_path() helpers, and the new test cases — were committed to main on 2026-04-14:

• Commit: 56c34ac4f — fix(browser): add termux PATH fallbacks
• Files: tools/browser_tool.py (lines 99–157) and tests/tools/test_browser_homebrew_paths.py
• The commit notes it was cherry-picked from PR Feat/termux install path, bug fixes termux #9846, which addressed the same underlying issue (browser_tool: _SANE_PATH missing Termux paths breaks browser on Android #5845).

Your analysis was correct and the fix is solid — it just arrived via a parallel path before this PR was merged. The linked issue #5845 can also be closed now that the fix is on main.

[alt-glitch]

Likely duplicate of #9927 (merged) — same fix: add Termux PATH fallbacks to browser tool.

[alt-glitch]

Likely duplicate of #9927 (merged) — same fix: add Termux PATH fallbacks to browser tool.