v0.7.1

Two new lightweight CLI commands surfaced by the v0.7.0
fresh-install UX test: when e2er run's tailer times out (or
the user ^C's it), there was no scripted way to re-attach,
inspect the current state, or cancel a runaway paper without
opening the dashboard.

Cross-lane

• e2er status <paper_id> — one-shot snapshot of a paper:
  status, mode/methodology, cost meter (with the
  cost_is_estimate marker on CLI backends), specialist call
  count, token total, workspace path, dashboard URL. Shows
  last_error verbatim when present so the user can diagnose
  REJECTED / PAUSED / FAILED without parsing the events log.
  With --tail, re-uses the same polling loop e2er run uses
  so the user can re-attach after ^C. Short-circuits on already-
  terminal status (no wasted polls). Hits the local API by
  default; respects E2ER_API_URL for remote inspection.
• e2er cancel <paper_id> — POSTs the /cancel endpoint
  with a confirmation prompt (skippable via --yes). Surfaces
  the title + current status + spend-so-far before the user
  confirms so they don't cancel by accident. Terminal-status
  short-circuit. Treats post-cancel 404 as success (the paper
  finished while we were asking; that's what the user wanted).
  Brief post-cancel poll so the user sees the CANCELLED
  transition land before the shell returns.
• Cost output now formats with two decimals. Pre-fix
  e2er status showed $8.462921999999999; now $8.46. Float
  noise was reaching the user-facing string when the API
  returned high-precision cost totals.
• _poll_status now treats rejected as terminal. Pre-fix
  the e2er run tailer kept polling forever on REJECTED papers
  (a v0.5+ status it didn't know about). Observed during fresh-
  install testing on paper 2ca473aa.

Test counts

• Mocked suite: 581 passed (was 554 in v0.7.0; +27 cli_status).
• 27 new tests in tests/test_cli_status.py covering
  formatters, exit codes, the unreachable-API branch, the
  confirmation prompt, and the post-cancel-404 race handling.

Known follow-up (v0.7.2 candidate)

• e2er resume <paper_id> — natural complement to cancel.
  PAUSED papers can be resumed via curl POST /resume today;
  a CLI command would close the same UX gap that status and
  cancel close. Out of scope for v0.7.1.