docs: drop merge-gate scope from PRD/docs

Branch protection isn't being applied; remove the README CI section,
the protection + gate-verification sections of docs/ci.md, and the
matching success-criteria / scope items from PRD 0002. Workflow itself
is unchanged.

Assisted-by: Claude Code

README.md

@@ -39,30 +39,6 @@ The container is removed automatically when the session ends. If the script
 is killed with SIGKILL the exit trap won't fire and the container may be
 left running; remove it with `docker rm -f <container-name>`.
 
-## CI
-
-Every push to a PR (and every push to `main`) runs the full test suite
-on Gitea Actions via `.gitea/workflows/test.yml`. The status badge at
-the top of this README links to the workflow's run history; the same
-check appears on each PR.
-
-Reading the check:
-
-- Green — `tests/run_tests.py` exited 0 on the runner.
-- Red — at least one test failed (or the workflow itself errored).
-  Click through to the run, expand the failing step, and read the
-  unittest output. Reproduce locally with `tests/run_tests.py` (or
-  `tests/run_tests.py unit` if you don't have Docker handy);
-  integration tests skip cleanly when Docker isn't reachable.
-- Skipped tests — expected when the runner has no Docker daemon. They
-  still leave the job green; if you actually want them executed,
-  ensure Docker is available on the runner host.
-
-Pushing a fix to a red PR re-triggers the workflow automatically — no
-manual rerun needed. Branch protection on `main` requires this check
-to be green before the merge button is enabled; see [`docs/ci.md`](docs/ci.md)
-for how those rules are configured.
-
 ## Egress
 
 Agent containers route HTTP / HTTPS traffic through a per-agent