ci: add CI OK aggregator gate (#20)

Remove paths-ignore from CI triggers so the workflow always fires on PRs.
Add dorny/paths-filter@v4 to detect code vs docs-only changes.
Gate all jobs behind the path-filter output.
Add final 'ok' job that aggregates all results into a single required check.

Author: CameronBrooks11

.github/workflows/ci.yml

@@ -3,12 +3,8 @@ name: CI
 on:
   push:
     branches: [main]
-    paths-ignore:
-      - '**/*.md'
   pull_request:
     branches: [main]
-    paths-ignore:
-      - '**/*.md'
 
 concurrency:
   group: fluxgraph-ci-${{ github.ref }}
@@ -18,8 +14,26 @@ env:
   VCPKG_COMMIT: "66c0373dc7fca549e5803087b9487edfe3aca0a1"
 
 jobs:
+  changes:
+    name: Detect code changes
+    runs-on: ubuntu-24.04
+    permissions:
+      pull-requests: read
+    outputs:
+      code: ${{ steps.filter.outputs.code }}
+    steps:
+      - uses: actions/checkout@v6
+      - uses: dorny/paths-filter@v4
+        id: filter
+        with:
+          filters: |
+            code:
+              - '!(**/*.md)'
+
   python-lint:
     name: Python Linting (ruff)
+    needs: [changes]
+    if: needs.changes.outputs.code == 'true'
     runs-on: ubuntu-24.04
     timeout-minutes: 10
 
@@ -48,6 +62,8 @@ jobs:
 
   python-typecheck:
     name: Python Type Checking (mypy)
+    needs: [changes]
+    if: needs.changes.outputs.code == 'true'
     runs-on: ubuntu-24.04
     timeout-minutes: 10
 
@@ -74,6 +90,8 @@ jobs:
 
   linux-matrix:
     name: Linux ${{ matrix.lane }}
+    needs: [changes]
+    if: needs.changes.outputs.code == 'true'
     runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
@@ -148,6 +166,8 @@ jobs:
 
   strict-dimensional-validation:
     name: Strict dimensional validation
+    needs: [changes]
+    if: needs.changes.outputs.code == 'true'
     runs-on: ubuntu-24.04
     timeout-minutes: 30
 
@@ -187,6 +207,8 @@ jobs:
 
   windows-core:
     name: Windows core-only
+    needs: [changes]
+    if: needs.changes.outputs.code == 'true'
     runs-on: windows-2025
 
     steps:
@@ -210,6 +232,8 @@ jobs:
 
   windows-diagram:
     name: Windows diagram-dot
+    needs: [changes]
+    if: needs.changes.outputs.code == 'true'
     runs-on: windows-2025
 
     steps:
@@ -233,6 +257,8 @@ jobs:
 
   diagram-render-smoke:
     name: Diagram Render Smoke
+    needs: [changes]
+    if: needs.changes.outputs.code == 'true'
     runs-on: ubuntu-24.04
 
     steps:
@@ -265,7 +291,22 @@ jobs:
           test -s "$OUT"
 
   version-sync:
+    needs: [changes]
+    if: needs.changes.outputs.code == 'true'
     uses: anolishq/.github/.github/workflows/version-sync.yml@01b61259e549666b145d941a5aa8a851b98ec399 # main
     with:
       python-version: '3.12'
       working-directory: '.'
+
+  ok:
+    name: ok
+    if: always()
+    needs: [changes, python-lint, python-typecheck, linux-matrix, strict-dimensional-validation, windows-core, windows-diagram, diagram-render-smoke, version-sync]
+    runs-on: ubuntu-24.04
+    timeout-minutes: 5
+    steps:
+      - name: Fail if any upstream job failed or was cancelled
+        if: contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled')
+        run: exit 1
+      - name: Pass
+        run: echo 'All checks passed or were skipped'