chore: migrate autodev state file to current format

Co-authored-by: Cursor <cursoragent@cursor.com>

_docs/_autodev_state.md

@@ -0,0 +1,13 @@
+# Autodev State
+
+## Current Step
+flow: existing-code
+step: 10
+name: Implement
+status: in_progress
+sub_step:
+  phase: 0
+  name: awaiting-invocation
+  detail: ""
+retry_count: 0
+cycle: 1

_docs/_autopilot_state.md

@@ -1,9 +0,0 @@
-# Autopilot State
-
-## Current Step
-flow: existing-code
-step: 9
-name: Implement
-status: in_progress
-sub_step: 1 — Parse and compute batches
-retry_count: 0