Closes#1808.
#1797 moved the compute-time budget into Settings → Performance & Device, but
three branches of _timeout_guidance still told the user to raise
OMNIVOICE_GENERATE_TIMEOUT_S. That sends someone to set an environment variable
for a value the app now exposes as a control — and on Windows, setting one
durably is the trap this project's own docs warn against.
Nothing about the mechanism changed: the variable still works and still takes
precedence over the setting. Only which of the two the message names.
Two existing tests asserted the env var appears in that text. They predate
#1797 and were pinning the behaviour this issue reports as wrong, so they now
assert the control instead. A third test guards the whole class rather than the
three instances, so a branch added later cannot quietly reintroduce it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017ypcgSsh5j2PEonSJiAU1S
