ci(I1): dedicated fast-fail ruff lint lane

ruff is pre-installed in the ci-python image, so a new `lint` job runs it
with no dependency install and fails in seconds — surfacing the common lint
bounce class without waiting on the backend job's ~30-60s wheel install.
Dropped the now-redundant ruff step from backend-lint-and-test (same job
name, required-checks unchanged).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.forgejo/workflows/ci.yml

@@ -1,7 +1,8 @@
 name: CI
 
 # CI lanes per FabledRulebook/forgejo.md "CI philosophy":
-#   - backend-lint-and-test: ruff + `pytest -m "not integration"`, no service containers.
+#   - lint: ruff only, no dep install — fast-fail for the common lint bounce.
+#   - backend-lint-and-test: `pytest -m "not integration"`, no service containers.
 #   - frontend-build: vitest unit + vite build.
 #   - integration: pgvector + redis service containers; alembic + `pytest -m integration`.
 
@@ -14,6 +15,20 @@ on:
   # (single-operator Forgejo repo) so push coverage is complete.
 
 jobs:
+  # Fast-fail lint lane. ruff is pre-installed in the ci-python image, so
+  # this runs with NO dependency install and surfaces the most common bounce
+  # class (lint: I001 / UP037 / ASYNC109 / W293 …) in seconds — instead of
+  # after the backend job's ~30-60s wheel install. ruff is static analysis,
+  # so no DB/secret env is needed.
+  lint:
+    runs-on: python-ci
+    container:
+      image: git.fabledsword.com/bvandeusen/ci-python:3.14
+    steps:
+      - uses: actions/checkout@v4
+      - name: Ruff lint
+        run: ruff check backend/ tests/ alembic/
+
   backend-lint-and-test:
     runs-on: python-ci
     container:
@@ -51,9 +66,8 @@ jobs:
             pip install -r requirements.txt pytest pytest-asyncio
           fi
 
-      - name: Ruff lint
-        run: ruff check backend/ tests/ alembic/
-
+      # Ruff moved to the dedicated fast `lint` job above (fails in seconds,
+      # no dep install). This job is now unit tests only.
       - name: Pytest (unit only — integration runs in the integration job)
         run: pytest tests/ -v -m "not integration"