feat(harness): P5 — customization manifest (rcust)

One block at run start answering "what does this recipe customize?" across every surface
(non-default recipe_meta keys, ops.py pre-ops, install_steps.sh, compose.ccci.yml, lifecycle
overlays by source, custom-test counts, active CCCI_SKIP_GENERIC* env overrides — !!-flagged when
riding a CI run, P2c), printed to the run log and embedded verbatim in results.json under
"customization". Pure presentation — building/printing it never influences a verdict; the
manifest honors the HC2 repo-local gate so it never advertises code the run will not execute.

Unit tests: synthetic recipe exercising every surface -> complete + deterministic + JSON-clean;
HC2 invisibility; env-override flagging; render golden lines; build_results threads the dict
verbatim (key always present, None when absent).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

runner/run_recipe_ci.py

@@ -58,6 +58,9 @@ from harness import (  # noqa: E402
 from harness import (  # noqa: E402
     deps as deps_mod,
 )
+from harness import (  # noqa: E402
+    manifest as manifest_mod,
+)
 from harness import (  # noqa: E402
     meta as meta_mod,
 )
@@ -880,6 +883,12 @@ def main() -> int:
     repo_local = snapshot_recipe_tests(recipe)
     meta = meta_mod.load(recipe)
 
+    # Customization manifest (rcust P5, R4): ONE block answering "what does this recipe
+    # customize?" across all surfaces — printed here and embedded verbatim in results.json under
+    # "customization". Pure presentation; never influences a verdict.
+    customization = manifest_mod.build(recipe, meta, repo_local)
+    print("\n" + manifest_mod.render(recipe, customization) + "\n", flush=True)
+
     # WC4/WC7: opt-in `--quick` fast lane. Requires an existing data-warm canonical; if none, fall
     # back cleanly to the full COLD run below so the PR is still tested (DECISIONS Phase-2w).
     if os.environ.get("CCCI_QUICK") == "1" or os.environ.get("MODE") == "quick":
@@ -1249,6 +1258,7 @@ def main() -> int:
             screenshot=screenshot_rel,  # Phase 3 U1 (R4): relative PNG name iff capture succeeded
             finished_ts=time.time(),
             expected_na=meta.EXPECTED_NA,  # declared intentional-skip map (recipe_meta)
+            customization=customization,  # rcust P5: the run-start manifest, verbatim
         )
         # Real (if narrow) leak check: no known infra-secret value may appear in the artifact (R7).
         blob = json.dumps(data)