ci: add CODEOWNERS, restrict Dependabot to patch bumps, make test workflows always-run (#3778)

- CODEOWNERS: default owners @Salazareo @ProgrammerIn-wonderland @jelveh
  @jfcastro92, plus @reynaldichernando for src/docs.
- dependabot.yml: ignore semver-minor/major npm updates, patch only.
- backend-tests.yaml / puterjs-tests.yaml: trigger unconditionally and gate
  the real work behind a dorny/paths-filter job instead of a workflow-level
  path filter, so the checks always report (skipped when irrelevant) and
  can be marked required. Also pins matrix job names to the artifact label
  instead of the branch ref, which previously made the check name change
  per PR and unusable as a required check.

.github/workflows/puterjs-tests.yaml

@@ -1,28 +1,42 @@
 name: Puter.js API Tests
 
-# Runs on puter.js SDK changes — the suites live in src/puter-js/tests,
-# so test changes are covered by the same glob — plus the pieces the
-# runners depend on: the worker preamble, the in-memory test env in
-# testUtil, and the backend vitest config the API-tests config extends.
-# Backend and extension changes run backend-tests.yaml instead.
+# Always triggers so it can be a required PR check; the `changes` job below
+# decides whether puter.js-relevant paths actually changed (the suites live
+# in src/puter-js/tests, so test-only changes are covered by the same glob,
+# plus the pieces the runners depend on: the worker preamble, the in-memory
+# test env in testUtil, and the backend vitest config the API-tests config
+# extends), and every other job is skipped — not absent — when they didn't,
+# which still satisfies a required check. Backend and extension changes run
+# backend-tests.yaml instead.
 on:
   pull_request:
     types: [opened, synchronize, reopened]
-    paths:
-      - 'src/puter-js/**'
-      - 'src/worker/**'
-      - 'src/backend/testUtil.ts'
-      - 'src/backend/vitest.config.ts'
-      - 'tools/**'
-      - 'package.json'
-      - 'package-lock.json'
-      - '.github/workflows/puterjs-tests.yaml'
 
 permissions:
   contents: read
   pull-requests: write
 
 jobs:
+  changes:
+    runs-on: ubuntu-latest
+    outputs:
+      puterjs: ${{ steps.filter.outputs.puterjs }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dorny/paths-filter@v3
+        id: filter
+        with:
+          filters: |
+            puterjs:
+              - 'src/puter-js/**'
+              - 'src/worker/**'
+              - 'src/backend/testUtil.ts'
+              - 'src/backend/vitest.config.ts'
+              - 'tools/**'
+              - 'package.json'
+              - 'package-lock.json'
+              - '.github/workflows/puterjs-tests.yaml'
+
   # The JSDoc in src/puter-js/src is the source of truth for the SDK's public
   # types. The declarations shipped to npm are generated from it at build time
   # and never committed, so what needs guarding is the JSDoc itself: this
@@ -32,6 +46,8 @@ jobs:
   # Its own job rather than a step in `test`: that one builds bundles and
   # installs a browser, and this needs neither.
   types:
+    needs: changes
+    if: needs.changes.outputs.puterjs == 'true'
     runs-on: ubuntu-latest
 
     steps:
@@ -51,6 +67,8 @@ jobs:
         run: npm run check:puterjs:types
 
   test:
+    needs: changes
+    if: needs.changes.outputs.puterjs == 'true'
     runs-on: ubuntu-latest
 
     steps:
@@ -84,6 +102,12 @@ jobs:
   # backend-tests.yaml. This run uses the istanbul-instrumented bundle
   # (the `test` job above keeps exercising the production build).
   coverage:
+    needs: changes
+    if: needs.changes.outputs.puterjs == 'true'
+    # Overrides the default matrix naming, which would otherwise bake the
+    # base/head branch name (matrix.ref) into the check name — making it a
+    # different string on every PR and impossible to pin as a required check.
+    name: coverage (${{ matrix.artifact }})
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -131,8 +155,8 @@ jobs:
           if-no-files-found: ignore
 
   report-coverage:
-    needs: coverage
-    if: always()
+    needs: [changes, coverage]
+    if: always() && needs.changes.outputs.puterjs == 'true'
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository