feat(2): Q0.1/Q0.2 — harness.http + discovery recurses functional/playwright (Phase 2)

- runner/harness/http.py: canonical Phase-2 recipe-test HTTP API (vendored from
  recipe-maintainer/utils/tests/helpers.py): http_get/http_post, retry variants,
  wait_for_http, assert_converges. JSON-parsing, header support, form/JSON POST
  bodies, transport-failure -> status=0. Self-contained (cc-ci does not import
  recipe-maintainer at runtime per DECISIONS Phase 2).
- harness.discovery.custom_tests now also recurses into
  tests/<recipe>/{functional,playwright}/test_*.py (Phase 2 §4.1 layout) while
  excluding lifecycle test_<op>.py names and honoring the HC2 repo-local gate.
- Unit tests:
    tests/unit/test_http.py — in-process http.server fixture; deterministic
    proofs of parsing/retry/convergence semantics, no network egress.
    tests/unit/test_discovery_phase2.py — functional/+playwright/ recursion
    + HC2 gate still applies to subdirs.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

runner/harness/discovery.py

@@ -101,16 +101,30 @@ def resolve_op(recipe: str, op: str, repo_local_dir: str | None) -> tuple[str, s
 
 def custom_tests(recipe: str, repo_local_dir: str | None) -> list[tuple[str, str]]:
     """All non-lifecycle test_*.py from cc-ci's tests/<recipe>/ and (if approved) the recipe's
-    repo-local tests/. These have no generic equivalent and run only when present (opt-in), additively
-    from both. Repo-local is consulted only for allowlist-approved recipes (HC2)."""
+    repo-local tests/. Discovered locations (Phase 2 §4.1):
+      - the top-level dir   tests/<recipe>/test_*.py  (legacy + cross-cutting)
+      - functional/         tests/<recipe>/functional/test_*.py  (parity ports + recipe-specific)
+      - playwright/         tests/<recipe>/playwright/test_*.py  (UI flows P6)
+    Files named `test_<op>.py` (lifecycle ops) are excluded from this list — the orchestrator runs
+    those in their lifecycle tier, not the custom one. Repo-local is consulted only for
+    allowlist-approved recipes (HC2)."""
     lifecycle_names = {f"test_{op}.py" for op in LIFECYCLE_OPS}
+    subdirs = ("functional", "playwright")
     found: list[tuple[str, str]] = []
     for source, d in (("cc-ci", cc_ci_dir(recipe)), ("repo-local", _gated(recipe, repo_local_dir))):
         if not d or not os.path.isdir(d):
             continue
+        # top-level (legacy / cross-cutting tests not under functional/playwright)
         for p in sorted(glob.glob(os.path.join(d, "test_*.py"))):
             if os.path.basename(p) not in lifecycle_names:
                 found.append((source, p))
+        # functional/ and playwright/ subdirs (Phase 2 §4.1)
+        for sub in subdirs:
+            for p in sorted(glob.glob(os.path.join(d, sub, "test_*.py"))):
+                # Phase-2 layout: lifecycle ops never live under functional/playwright, but be
+                # explicit so a misfiled file doesn't silently get double-run.
+                if os.path.basename(p) not in lifecycle_names:
+                    found.append((source, p))
     return found