fix: devloop continue misrouted as NL task; gate timeouts leave no recovery path

[Copilot]

devloop continue TASK-ID was treated as natural language, spawning a new architect phase on top of an already-completed worker and opening a duplicate Live View pane. Gate timeouts also dropped users to a bare prompt with no recovery guidance.

Changes

Command dispatcher

• Added continue as alias for resume — devloop continue TASK-ID now routes to cmd_resume

NL router TASK-ID guard

• Unknown commands are now scanned for TASK-[0-9]{8}-[0-9]{6} args before NL routing fires
• On match: prints devloop resume <id> / devloop status <id> hints and exits cleanly — no architect spawn, no duplicate pane

Gate rejection recovery hints

• _approval_gate() timeout path now prints devloop resume $DEVLOOP_CURRENT_SESSION_ID when a session ID is in scope
• All plan/diff rejection exits in cmd_run and cmd_resume print the same targeted hint

cmd_resume now handles gate-rejected sessions

• rejected-at-plan and rejected-at-diff removed from the terminal-status early-exit; only approved and rejected (reviewer verdict) are treated as non-resumable
• Resuming a rejected-at-plan session re-runs the plan gate → worker → diff gate (existing _compute_resume_from logic already returns worker for this case)
• Resuming a rejected-at-diff session re-runs the diff gate via a new _resume_diff_gate flag set when cur_status == rejected-at-diff && next_phase == reviewer, triggering the full diff-gate loop before entering the reviewer

# Before: misrouted
$ devloop continue TASK-20260517-001721
Unknown command — interpreting as natural language task
[1] Architecting...  ← wrong, spawns new pipeline

# After: correct
$ devloop continue TASK-20260517-001721
▶ Resuming TASK-20260517-001721
  From: worker   Next: diff gate

[shaifulshabuj]

Implementation is clean: rejected-at-plan and rejected-at-diff are now resumable. The diff-gate override for rejected-at-diff correctly re-presents only the gate without re-running the worker. Terminal states are now only approved and reviewer-rejected. Approving.

[Copilot]

Pull request overview

Allows devloop resume to recover sessions previously stuck in rejected-at-plan / rejected-at-diff states (which were treated as terminal). Previously these statuses fell through rejected-at-* glob filters and were skipped; now only reviewer-rejected (rejected) and approved are treated as truly terminal. The diff-gate override is extended so resuming a rejected-at-diff session re-presents only the diff gate without re-running the worker.

Changes:

• Narrow terminal-status filters in --list, newest-session selection, and the early-exit guard from approved|rejected|rejected-at-* to just approved|rejected.
• Extend the existing timed-out-at-diff override to also handle rejected-at-diff, setting next_phase=diff-gate.
• Print an informational hint when resuming a rejected-at-plan session and update the --help text to list the newly resumable statuses.