ci: switch all non-fast jobs to comment triggers

Every CI job except test-fast and mirror-to-codeberg now runs only
when explicitly requested via a PR comment, instead of on every push
or PR sync.  This keeps the Pi runner idle during WIP commits and lets
the author decide when to pay each job's cost.

Trigger commands:
  /test-cgal       → CGAL test suite (277 tests, ~5 min build + 31 s run)
  /quality-gates   → license/codespell/shellcheck/cgal-conventions (~30 s)
  /docs            → Doxygen build + warning summary (~2 min)
  /links           → Markdown internal link check (~10 s)

All comment-triggered jobs check:
  event is issue_comment
  AND comment is on a PR (issue.pull_request != null)
  AND comment body contains the trigger word
  AND checkout uses refs/pull/N/head (not the default branch)

Jobs that stay automatic:
  test-fast         — runs on every push (26 pure-math tests, < 5 s)
  mirror-to-codeberg — unchanged

Jobs that keep additional triggers:
  markdown-links — weekly cron (Mon 05:00 UTC) + workflow_dispatch
  doc-build      — workflow_dispatch (for manual runs outside a PR)

quality-gates drops `needs: test-fast` — it now runs independently
when comment-triggered (caller decides whether test-fast passed first).

CLAUDE.md CI pipeline table updated with all five jobs and their new
trigger descriptions.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/cpp-tests.yml

@@ -152,25 +152,25 @@ jobs:
 # ─────────────────────────────────────────────────────────────────────────────
 # Job 3 — quality-gates  (style + convention block)
 #
-# Cheap, deterministic checks that should never break unless a contributor
+# Trigger: write "/quality-gates" as a comment on any pull request.
-# introduces a regression.  Each gate is a script under scripts/quality/
-# and exits 0 only when its tree is clean.  These ran for weeks locally
-# at zero findings before being promoted here.
 #
-# Tools installed at job-start (the ci-cpp image already has python3 +
+# Cheap, deterministic checks (~30 s): license headers, CGAL conventions,
-# bash; we add codespell + shellcheck on top).  Total wall-time: ~30 s
+# codespell, shellcheck.  Runs independently of test-fast when comment-
-# on the eulernest runner.
+# triggered (no `needs:` — the caller decides when to invoke it).
-#
-# Strictly required for merges into main/dev — a regression fails the PR.
 # ─────────────────────────────────────────────────────────────────────────────
   quality-gates:
-    needs: test-fast
+    if: |
+      github.event_name == 'issue_comment' &&
+      github.event.issue.pull_request != null &&
+      contains(github.event.comment.body, '/quality-gates')
     runs-on: eulernest
     container:
       image: git.eulernest.eu/conformallab/ci-cpp:latest
 
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: refs/pull/${{ github.event.issue.number }}/head
 
       - name: Install codespell + shellcheck (job-local)
         run: |

.gitea/workflows/doc-build.yaml

@@ -1,34 +1,38 @@
 name: API Docs
 
+# Trigger: write "/docs" as a comment on any pull request.
+# Also available via workflow_dispatch for manual runs outside a PR context.
+
 on:
-  push:
+  issue_comment:
-    branches:
+    types: [created]
-      - main
+  workflow_dispatch: {}
-  pull_request:
 
 # ─────────────────────────────────────────────────────────────────────────────
 # Doc-build — informational only
 #
 # Generates Doxygen HTML from the public headers and reports warning
 # statistics.  Does NOT block merges: `continue-on-error: true` ensures
-# warnings or extraction issues never fail the CI gate.  When Doxygen
+# warnings or extraction issues never fail.
-# coverage is denser (Phase 8c), this job can be promoted to a hard
-# requirement and the HTML deployed to Pages.
 #
-# Note: Gitea Actions on GHES does not support `actions/upload-artifact@v4`,
+# Trigger: "/docs" PR comment (or workflow_dispatch for manual runs).
-# so HTML artifact upload is intentionally omitted.  The warning summary
+# Checkout uses refs/pull/N/head when triggered via comment.
-# in the job log is the primary reviewer signal; reviewers who want the
-# HTML can rebuild it locally with `cmake --build build --target doc`.
 # ─────────────────────────────────────────────────────────────────────────────
 jobs:
   doc-build:
-    if: github.event_name == 'pull_request'
+    if: |
+      github.event_name == 'workflow_dispatch' ||
+      (github.event_name == 'issue_comment' &&
+       github.event.issue.pull_request != null &&
+       contains(github.event.comment.body, '/docs'))
     runs-on: eulernest
     container:
       image: git.eulernest.eu/conformallab/ci-cpp:latest
     continue-on-error: true   # never block the merge
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event_name == 'issue_comment' && format('refs/pull/{0}/head', github.event.issue.number) || github.ref }}
 
       - name: Generate API documentation
         run: doxygen Doxyfile 2>&1 | tee doxygen.log

.gitea/workflows/markdown-links.yml

@@ -1,35 +1,36 @@
 name: Markdown link check
 
 # Verify every internal markdown link in the repo resolves to an existing
-# file (or anchor).  External http(s) links are also probed but with a
+# file (or anchor).
-# loose timeout — flaky third-party hosts must not break our CI.
 #
-# Trigger: PRs that touch any *.md file, plus a weekly cron so external
+# Triggers:
-# link rot is caught even when nobody is editing docs.
+#   - "/links" as a PR comment  (manual, on the PR branch)
+#   - Weekly cron Mon 05:00 UTC (catches link rot without any PR activity)
+#   - workflow_dispatch          (manual run on any branch)
 
 on:
-  pull_request:
+  issue_comment:
-    paths:
+    types: [created]
-      - "**/*.md"
-      - ".gitea/workflows/markdown-links.yml"
-  push:
-    branches:
-      - main
-    paths:
-      - "**/*.md"
-      - ".gitea/workflows/markdown-links.yml"
   schedule:
     - cron: "0 5 * * 1"   # Monday 05:00 UTC weekly link-rot check
   workflow_dispatch: {}
 
 jobs:
   check:
+    if: |
+      github.event_name == 'schedule' ||
+      github.event_name == 'workflow_dispatch' ||
+      (github.event_name == 'issue_comment' &&
+       github.event.issue.pull_request != null &&
+       contains(github.event.comment.body, '/links'))
     runs-on: eulernest
     container:
       image: git.eulernest.eu/conformallab/ci-cpp:latest
 
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event_name == 'issue_comment' && format('refs/pull/{0}/head', github.event.issue.number) || github.ref }}
 
       # ── Pure-python internal link check (no external network needed) ────
       # We use the same logic that found the 2 broken links before the

CLAUDE.md

@@ -264,9 +264,11 @@ Three jobs in `.gitea/workflows/cpp-tests.yml`:
 
 | Job | CMake flags | Deps | Triggers on | Status |
 |---|---|---|---|---|
-| `test-fast` | *(none)* | Eigen + GTest only | all branches | **active** |
+| `test-fast` | *(none)* | Eigen + GTest only | all branches (auto) | **active** |
-| `test-cgal` | `-DWITH_CGAL_TESTS=ON -DCONFORMALLAB_LOW_MEMORY_BUILD=ON` | + Boost | `/test-cgal` PR comment | **active** (comment-triggered, 2026-05-31) |
+| `test-cgal` | `-DWITH_CGAL_TESTS=ON -DCONFORMALLAB_LOW_MEMORY_BUILD=ON` | + Boost | `/test-cgal` PR comment | **active** |
-| `quality-gates` | *(none)* | + codespell, shellcheck | all branches (`needs: test-fast`) | **active** |
+| `quality-gates` | *(none)* | + codespell, shellcheck | `/quality-gates` PR comment | **active** |
+| `doc-build` | *(none)* | Doxygen | `/docs` PR comment or `workflow_dispatch` | **active** |
+| `markdown-links` | *(none)* | python3 | `/links` PR comment, weekly cron, `workflow_dispatch` | **active** |
 
 Runner: `eulernest` — self-hosted Raspberry Pi, ARM64, Ubuntu 22.04. Docker image: `git.eulernest.eu/conformallab/ci-cpp:latest`. `test-cgal` and `quality-gates` both need `test-fast` to pass first (`needs: test-fast`).