fix(ci): treat 'permissions: write-all' as a write-permission gate

`WRITE_PERMISSION_PATTERN` in `validate-workflow-security.js`
enumerates named GitHub Actions scopes (`contents: write`,
`issues: write`, etc.) to decide whether a workflow needs to:
  - disable `persist-credentials` on `actions/checkout`
  - pass `--ignore-scripts` to `npm ci`

The pattern misses the top-level shorthand `permissions:
write-all`, which is the strictly broader form — it grants every
named scope write access in a single line. As a result, a
workflow that opts into write-all currently slips both gates.

Reproduced on `main` before this commit:

  $ cat /tmp/bad.yml
  name: bad
  on: [push]
  permissions: write-all
  jobs:
    do:
      runs-on: ubuntu-latest
      steps:
        - uses: actions/checkout@v4
        - run: npm ci

  $ ECC_WORKFLOWS_DIR=/tmp node scripts/ci/validate-workflow-security.js
  Validated workflow security for 1 workflow files
  $ echo $?
  0

Expected: at least two violations (missing `persist-credentials:
false`, missing `--ignore-scripts`).
Actual: passes silently.

Fix: add a sibling pattern `WRITE_ALL_PATTERN` that matches
`^\s*permissions:\s*write-all\b` and OR it with
`WRITE_PERMISSION_PATTERN` at the single gate. Both top-level
and job-level `permissions:` blocks satisfy the `^\s*` prefix.

After this commit the reproduction above exits 1 with:

  ERROR: bad.yml:8 - workflows with write permissions must disable checkout credential persistence
  ERROR: bad.yml:9 - workflows with write permissions must install npm dependencies with --ignore-scripts

Three new regression tests in `tests/ci/validate-workflow-security.test.js`:
  - rejects write-all + credential-persisting checkout
  - rejects write-all + `npm ci` without `--ignore-scripts`
  - allows write-all when both gates are satisfied (no over-block)

Test count: 14 → 17 in this file; full `yarn test` still green.

A separate `refs/pull/N/merge` bypass under `pull_request_target`
exists in the same validator and is fixed in the next commit.

tests/ci/validate-workflow-security.test.js

@@ -155,6 +155,34 @@ function run() {
     assert.strictEqual(result.status, 0, result.stderr || result.stdout);
   })) passed++; else failed++;
 
+  // `permissions: write-all` is GitHub Actions' shorthand for granting every
+  // scope write access. The named-scope pattern only catches `contents: write`,
+  // `issues: write`, etc., so workflows that opt into write-all were silently
+  // exempted from the persist-credentials and --ignore-scripts gates.
+
+  if (test('rejects checkout credential persistence in workflows with permissions: write-all', () => {
+    const result = runValidator({
+      'unsafe-write-all-checkout.yml': `name: Unsafe\non:\n  workflow_dispatch:\npermissions: write-all\njobs:\n  release:\n    runs-on: ubuntu-latest\n    steps:\n      - uses: actions/checkout@v4\n      - run: npm ci --ignore-scripts\n`,
+    });
+    assert.notStrictEqual(result.status, 0, 'Expected validator to fail on write-all + credential-persisting checkout');
+    assert.match(result.stderr, /write permissions must disable checkout credential persistence/);
+  })) passed++; else failed++;
+
+  if (test('rejects npm ci without ignore-scripts in workflows with permissions: write-all', () => {
+    const result = runValidator({
+      'unsafe-write-all-install.yml': `name: Unsafe\non:\n  workflow_dispatch:\npermissions: write-all\njobs:\n  audit:\n    runs-on: ubuntu-latest\n    steps:\n      - uses: actions/checkout@v4\n        with:\n          persist-credentials: false\n      - run: npm ci\n`,
+    });
+    assert.notStrictEqual(result.status, 0, 'Expected validator to fail on write-all + npm ci without --ignore-scripts');
+    assert.match(result.stderr, /npm ci must include --ignore-scripts/);
+  })) passed++; else failed++;
+
+  if (test('allows compliant workflow with permissions: write-all', () => {
+    const result = runValidator({
+      'safe-write-all.yml': `name: Safe\non:\n  workflow_dispatch:\npermissions: write-all\njobs:\n  release:\n    runs-on: ubuntu-latest\n    steps:\n      - uses: actions/checkout@v4\n        with:\n          persist-credentials: false\n      - run: npm ci --ignore-scripts\n`,
+    });
+    assert.strictEqual(result.status, 0, result.stderr || result.stdout);
+  })) passed++; else failed++;
+
   if (test('rejects actions/cache in workflows with id-token write', () => {
     const result = runValidator({
       'unsafe-oidc-cache.yml': `name: Unsafe\non:\n  push:\npermissions:\n  contents: read\n  id-token: write\njobs:\n  release:\n    runs-on: ubuntu-latest\n    steps:\n      - uses: actions/cache@v5\n        with:\n          path: ~/.npm\n          key: cache\n`,