chore(autodev): advance state to Step 10 (Implement) for cycle 2

Reconciliation: prior session completed Step 9 (New Task) which
produced AZ-531..AZ-538 in _docs/02_tasks/todo/ and refreshed the
_dependencies_table.md, but did not bump _autodev_state.md. Folder
state is authoritative per state.md rule #4; advancing the pointer.

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

_docs/_autodev_state.md

@@ -2,8 +2,8 @@
 
 ## Current Step
 flow: existing-code
-step: 9
-name: New Task
+step: 10
+name: Implement
 status: not_started
 sub_step:
   phase: 0