Fix 7 bugs in autopilot.py, add 43 tests
Fixes from functional correctness review:
- PHASE_PRIORITY: add code_review (was missing, caused wrong task selection)
- cmd_drive: implement→code_review (was illegal implement→bug_find)
- cmd_drive: add handlers for code_review and code_review:approved
- _all_tasks: skip tasks/complete/ (was showing completed tasks as phase=None)
- _all_tasks: recurse into subtasks/ (subtasks were invisible to autopilot)
- _all_tasks: use .automaton/tasks for non-framework projects (was project/tasks)
- is_terminal: only True for complete (human_intervention has legal transitions)
- needs_user_input: flag human_intervention as blocked (was auto-driving it)
Tests cover all 8 bugs: PHASE_PRIORITY ordering, every phase transition,
code_review handlers, complete/ exclusion, subtask recursion, project path,
terminal state, user-input detection, human_intervention handling.