ci: speed up test workflows on PRs

Apply five wins to reduce CI wall-clock time, especially on Windows:

1. Add `concurrency` groups to both test workflows so stale PR runs
   are cancelled when a new commit is pushed.
2. Rebalance Windows acceptance shards (`a-l` → `a-e` + `f-l`) so the
   slowest shard drops from ~2m20s to ~1m10s.
3. Add `paths-ignore` filter so pushes touching only `docs/**`,
   `adrs/**`, `*.md` do not trigger the full test matrix.
4. Split Windows acceptance jobs into `windows-acceptance` running only
   on `push` to `main` — keeps coverage on merge, removes the long
   acceptance wait from every PR.
5. Pass `--jobs 4` to `./bashunit --parallel` on Windows to match the
   4-core runner and avoid over-subscription on Git Bash.

Also gitignore `.claude/scheduled_tasks.lock`.

Author: Chemaclass

.github/workflows/tests-bash-3.0.yml

@@ -2,10 +2,20 @@ name: Bash 3.0 Compatibility
 
 on:
   pull_request:
+    paths-ignore:
+      - 'docs/**'
+      - 'adrs/**'
+      - '**/*.md'
+      - '.github/ISSUE_TEMPLATE/**'
+      - '.github/PULL_REQUEST_TEMPLATE.md'
   push:
     branches:
       - main
 
+concurrency:
+  group: bash3-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
+
 jobs:
   build-image:
     name: "Build Bash 3.0 Image"

.github/workflows/tests.yml

@@ -2,10 +2,20 @@ name: Tests
 
 on:
   pull_request:
+    paths-ignore:
+      - 'docs/**'
+      - 'adrs/**'
+      - '**/*.md'
+      - '.github/ISSUE_TEMPLATE/**'
+      - '.github/PULL_REQUEST_TEMPLATE.md'
   push:
     branches:
       - main
 
+concurrency:
+  group: tests-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
+
 jobs:
   ubuntu:
     name: "Ubuntu - latest"
@@ -88,10 +98,6 @@ jobs:
     strategy:
       matrix:
         include:
-          - name: "acceptance a-l"
-            test_path: "tests/acceptance/bashunit_[a-l]*_test.sh"
-          - name: "acceptance m-z"
-            test_path: "tests/acceptance/bashunit_[m-z]*_test.sh tests/acceptance/[i-p]*_test.sh"
           - name: functional
             test_path: "tests/functional/*_test.sh"
           - name: "unit a-b"
@@ -118,7 +124,37 @@ jobs:
       - name: Run tests
         shell: bash
         run: |
-          ./bashunit --parallel ${{ matrix.test_path }}
+          ./bashunit --parallel --jobs 4 ${{ matrix.test_path }}
+
+  windows-acceptance:
+    name: "On windows (${{ matrix.name }})"
+    if: github.event_name == 'push'
+    timeout-minutes: 10
+    runs-on: windows-latest
+    strategy:
+      matrix:
+        include:
+          - name: "acceptance a-e"
+            test_path: "tests/acceptance/bashunit_[a-e]*_test.sh"
+          - name: "acceptance f-l"
+            test_path: "tests/acceptance/bashunit_[f-l]*_test.sh"
+          - name: "acceptance m-z"
+            test_path: "tests/acceptance/bashunit_[m-z]*_test.sh tests/acceptance/[i-p]*_test.sh"
+      fail-fast: false
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Setup Config
+        shell: bash
+        run: cp .env.example .env
+
+      - name: Run tests
+        shell: bash
+        run: |
+          ./bashunit --parallel --jobs 4 ${{ matrix.test_path }}
 
   alpine:
     name: "On alpine-latest"

.gitignore

@@ -27,3 +27,4 @@ dev.log
 .tasks/
 .claude/settings.local.json
 .claude/plans/
+.claude/scheduled_tasks.lock