[AZ-406] Add blackbox_tests cross-cutting entry to module-layout.md

The 41 blackbox/e2e test tasks (AZ-406..AZ-446 under epic AZ-262) all
declare Component=Blackbox Tests, but module-layout.md had no matching
Per-Component Mapping entry. The implement skill's Step 4 (File
Ownership) requires every batch's component to be resolvable in
module-layout.md.

Add a `blackbox_tests` entry in the Shared / Cross-Cutting section
that owns the top-level `e2e/` directory (separate from `tests/`),
documents the public-boundary discipline (no SUT imports), and
clarifies that boundary-driven performance/resilience/security
scenarios live under `e2e/tests/<category>/` rather than under
`tests/perf|security|resilience/`.

Also update Layout Rule #7 to reflect the harness split and the
state file's sub_step to parse-and-detect-progress (Step 10 entry).

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

_docs/_autodev_state.md

@@ -4,10 +4,10 @@
 flow: greenfield
 step: 10
 name: Implement Tests
-status: not_started
+status: in_progress
 sub_step:
-  phase: 0
-  name: awaiting-invocation
+  phase: 1
+  name: parse-and-detect-progress
   detail: ""
 retry_count: 0
 cycle: 1