docs+comments: align plan with gitea PR-only CI and close remaining blockers

implementation.md

@@ -179,8 +179,8 @@ Every milestone follows the **Red → Green → Refactor** cycle. No production
 ### 3.3 Coverage Requirements
 
 - **Minimum 90% line coverage** on all `apps/` code, enforced via `pytest-cov` in CI
-- Coverage reports generated on every push; PRs blocked below threshold
-- E2E tests run nightly, not on every push (they are slow)
+- Coverage reports generated on every pull request; PRs blocked below threshold
+- E2E tests run nightly, not on every pull request (they are slow)
 
 ### 3.4 Test Organisation
 
@@ -212,10 +212,10 @@ class ArticlePageFactory(wagtail_factories.PageFactory):
     # Note: no is_featured — featured article is set on HomePage.featured_article only
 ```
 
-### 3.6 CI Pipeline (GitHub Actions)
+### 3.6 CI Pipeline (Gitea Actions)
 
 ```
-on: [push, pull_request]
+on: [pull_request]
 
 jobs:
   test:
@@ -232,6 +232,8 @@ jobs:
       - Run Playwright suite
 ```
 
+Rationale: all merges should flow through pull requests. Running the same checks on both `push` and `pull_request` duplicates work and wastes compute.
+
 ---
 
 ## Milestone 0 — Project Scaffold & Tooling
@@ -242,7 +244,7 @@ jobs:
 - `./manage.py runserver` starts without errors
 - `pytest` runs and exits 0 (no tests yet = trivially passing)
 - `ruff` and `mypy` pass on an empty codebase
-- GitHub Actions workflow file committed and green
+- Gitea Actions workflow file committed and green
 
 ### M0 — Tasks
 
@@ -271,7 +273,7 @@ jobs:
 - Add Prism.js and Alpine.js to `static/js/`; wire into `base.html`
 
 #### M0.5 — CI
-- Create `.github/workflows/ci.yml`
+- Create `.gitea/workflows/ci.yml`
 - Install `pytest-django`, `pytest-cov`, `ruff`, `mypy`, `factory_boy`, `wagtail-factories`
 - Create `pytest.ini` / `pyproject.toml` config pointing at `config.settings.development`
 - Write the only M0 test: a trivial smoke test that asserts `1 == 1` to confirm CI runs
@@ -1487,4 +1489,4 @@ A milestone is **Done** when all of the following are true:
 
 ---
 
-*This document is the source of truth for implementation order and test requirements. Revise it when requirements change — do not let it drift from the codebase.*
+*This document is the source of truth for implementation order and test requirements. Revise it when requirements change — do not let it drift from the codebase.*