Fix pre-existing issues and update README for v2.0

- Fix _infer_state_from_artifacts: SPEC-only maps to research (was bug_find)
- Fix cmd_validate_folder: corrupted .state files now error instead of silent fallback
- Fix upgrade.sh: remove || true, add python3 check, use git rev-parse --git-dir
- Update README.md with --project flag, --can-edit modes, --upgrade, enforcement layers
- Add 6 new tests for inference and validation fixes
- Complete hook-install-process and readme-upgrade-docs tasks

scripts/status.py

@@ -303,10 +303,8 @@ def _infer_state_from_artifacts(task_path: Path) -> Optional[str]:
         return "referee"
     if "ADVERSARIAL_BUG_REPORT.md" in artifacts and "BUG_REPORT.md" in artifacts:
         return "doc_review"
-    if "BUG_REPORT.md" in artifacts and "SPEC.md" in artifacts:
+    if "BUG_REPORT.md" in artifacts:
         return "adversarial_bug_find"
-    if "SPEC.md" in artifacts and "BUG_REPORT.md" not in artifacts:
-        return "bug_find"
     if "IMPLEMENTATION.md" in artifacts:
         return "bug_find"
     if "TEST_PLAN.md" in artifacts:
@@ -562,9 +560,11 @@ def cmd_validate_folder(args):
             return 1
     phase = _read_state(task_path)
     if phase is None:
-        phase = _infer_state_from_artifacts(task_path)
-    if phase is None:
-        phase = "unknown"
+        print(f"Task: {args.task}")
+        print(f"Phase: unknown (corrupted .state file)")
+        print(f"Folder validation: FAIL — .state file exists but is empty or unreadable.")
+        print(f"  Run 'python ~/.automaton/scripts/status.py --upgrade --task {args.task} --project <project-path>' to re-bootstrap .state file.")
+        return 1
     base = _base_phase(phase)
     forbidden = _check_forbidden_artifacts(task_path, base)
     print(f"Task: {args.task}")