Fix 11 automation gaps: dead-end phases, autopilot runtime, guard plugin, status.py bugs, Category 3 audit

- Fix decomposition:approved and human_intervention dead-end phases
- Add scripts/autopilot.py: real drive_all() implementation
- Fix guard plugin: throw Error instead of injecting user messages
- Fix status.py: double continue, _require_state, --list-states
- Add Category 3 (git-based modification) audit
- Add Category 5 (stuck-task detection) audit
- All 206 tests pass

tasks/fix-status-script-bugs/IMPLEMENTATION.md

@@ -0,0 +1,13 @@
+# IMPLEMENTATION.md — Fix Status Script Bugs
+
+## Changes Made
+- `scripts/status.py:504-510`: Removed neutered target-phase artifact check (restored `pass` — analysis showed it's redundant with current-phase check at 525-531)
+- `scripts/status.py:1007,1061`: Removed dead double `continue` statements
+- `scripts/status.py:523`: Changed `cmd_approve` to use `_require_state` instead of `_read_state` for consistency
+- `scripts/status.py:1088-1095`: Added `cmd_list_states` function and `--list-states` CLI argument
+
+## How It Works
+- `--list-states` prints all valid phases with approval requirements noted
+- Double continue dead code removed
+- cmd_approve rejects untracked tasks consistently
+- Target-phase check restored to `pass` (existing checks cover the cases correctly)