docs: document CI status check and main branch protection

Add a Gitea Actions test-status badge plus a short README "CI" section
covering how to read the check and what to do when it's red. Capture
the (out-of-tree) branch-protection rule on `main` in docs/ci.md so
the gate that requires the test check is reproducible from the repo
alone — covers both the Gitea UI path and the equivalent API call.

Refs: PRD 0002

Assisted-by: Claude Code

README.md

@@ -1,5 +1,7 @@
 # claude-bottle
 
+[![test](https://gitea.dideric.is/didericis/claude-bottle/actions/workflows/test.yml/badge.svg?branch=main)](https://gitea.dideric.is/didericis/claude-bottle/actions?workflow=test.yml)
+
 Spins up an isolated container for running Claude Code with a curated set of skills and env vars.
 
 ## Why "claude-bottle"?
@@ -37,6 +39,30 @@ 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

docs/ci.md

@@ -0,0 +1,83 @@
+# CI
+
+The test workflow lives at [`.gitea/workflows/test.yml`](../.gitea/workflows/test.yml).
+It runs `tests/run_tests.py` (full suite — unit + integration) on:
+
+- every push to a branch with an open pull request, and
+- every push to `main`.
+
+Integration tests need Docker on the runner; they skip cleanly via
+`tests/_docker.skip_unless_docker` when no daemon is reachable.
+
+## Branch protection on `main`
+
+Branch protection is **not** captured in tree — Gitea applies it via
+the repo settings UI / API, not a checked-in config file. Reproducing
+the rule on a fresh clone or migration therefore means re-applying the
+same setting through one of the two paths below.
+
+### Via the Gitea UI
+
+1. Go to the repo on `gitea.dideric.is`.
+2. **Settings** → **Branches** → **Branch protection rules** →
+   **Add rule**.
+3. **Branch name pattern:** `main`.
+4. Enable **Enable Status Check** and select the check named
+   `test / run tests/run_tests.py` (the workflow's job display name).
+   The check has to have run at least once on the repo for Gitea to
+   list it; push a no-op commit on a feature branch first if needed.
+5. (Recommended) Also enable **Require pull request before merging**
+   so changes to `main` always go through a PR — otherwise a direct
+   push to `main` bypasses the status check entirely.
+6. Save.
+
+After saving, open a PR. The "Merge" button should be disabled until
+the test check is green.
+
+### Via the Gitea API
+
+Equivalent call (requires an admin token in `$GITEA_TOKEN`):
+
+```sh
+curl -X POST \
+  -H "Authorization: token $GITEA_TOKEN" \
+  -H "Content-Type: application/json" \
+  https://gitea.dideric.is/api/v1/repos/didericis/claude-bottle/branch_protections \
+  -d '{
+    "rule_name": "main",
+    "enable_status_check": true,
+    "status_check_contexts": ["test / run tests/run_tests.py"],
+    "required_approvals": 0,
+    "block_on_outdated_branch": false
+  }'
+```
+
+The exact field for the check name is
+`status_check_contexts` (an array of glob patterns). The Gitea
+Actions check appears under
+`<workflow-name> / <job-name>` — here `test / run tests/run_tests.py`.
+Confirm the actual rendered context string in **Repo → Actions →
+<run> → Job summary** before pasting into the API call; Gitea
+versions occasionally tweak the formatting and a typo here silently
+matches no checks (rule loads, but never blocks).
+
+To inspect the live rule:
+
+```sh
+curl -H "Authorization: token $GITEA_TOKEN" \
+  https://gitea.dideric.is/api/v1/repos/didericis/claude-bottle/branch_protections
+```
+
+## Verifying the gate
+
+Once the rule is in place, prove it works once with a deliberately-failing
+test on a throwaway branch:
+
+1. Create a branch (`gate-test-DELETEME`), add a test that fails (e.g.
+   `self.assertTrue(False)`), push, open a PR.
+2. Wait for the check to go red. Confirm the "Merge" button is
+   disabled / shows the unmet status check.
+3. Close the PR and delete the branch. Do not merge.
+
+This is a one-time check after applying the rule, not a recurring
+exercise.