[hyperdrivebeep]

Stalled file uploads

• A file upload had no progress deadline and no cancel button. stageFile now uses
  XMLHttpRequest with upload progress: if no bytes are sent for 2 minutes, the upload stops
  with a Korean and English message that no source was connected. A cancel button is shown
  while files are sent and while the server processes them; once all bytes are sent there
  is no automatic deadline.
• Uploading several files now stages every file first and only then connects them, so a
  cancel or stall connects nothing. Progress shows the sent percentage, then a processing
  message. Staged but unconnected files are not registered as sources. Server RPCs are
  unchanged.

Workspace location policy

• The workspace location is classified before the workspace lock and the database open.
  Known sync roots (cloud sync status, OneDrive and registry-registered sync roots),
  network shares and drives, and Windows-to-WSL bridges are refused. Locations that cannot
  be confirmed (including macOS for now) need a one-time confirmation that is bound to the
  folder identity and reasons and keeps a short warning visible. Removable drives confirmed
  not to be under a sync root are allowed with a warning; fixed local drives with no sync or
  network signal are allowed.
• The CLI exits with 4 (refused) or 5 (needs confirmation) and asks only on an interactive
  terminal; serve and desktop check before taking the lock; HTTP returns 503 with the same
  text; hosted review mode is unchanged. A new accept-location command confirms or forgets
  a location, and 'thoth workspace' shows the assessment. Workspace IDs are unchanged.
• This is a support policy, not a safety guarantee; README, INSTALL, KNOWN_LIMITATIONS and
  the RPC catalog say so.

Test reliability

• The workspace runtime lock test's helper now publishes its PID marker atomically, so the
  test cannot read an empty marker under load.

Verification: full suite on the pre-fix tree - 5586 Python tests, 4 failures. Two were the
CLI help contract missing the new command, fixed here. Two were timing issues under load:
a browser close check that passes when run alone, and the runtime lock marker race fixed
here. After the fix the affected CLI, lock and location tests pass; web tests, lint,
typecheck, build, ruff, architecture and module budget checks, and the README quick-start
smoke test passed in the full run.