[github-actions] Add code-owner-approved label workflow

Add a workflow that automatically manages a code-owner-approved label
on PRs when component-specific codeowners submit approvals. This helps
maintainers prioritize PRs that have domain-expert sign-off.

The workflow triggers on pull_request_review events and recalculates
the label based on all current reviews. Only individual component
codeowners count - the catch-all @esphome/core team is excluded.
Uses last-match-wins semantics for CODEOWNERS pattern matching.

Also extracts shared CODEOWNERS parsing logic into a reusable module
at .github/scripts/codeowners.js and updates codeowner-review-request
and auto-label-pr workflows to use it.

.github/workflows/codeowner-approved-label.yml

@@ -0,0 +1,159 @@
+# This workflow adds/removes a 'code-owner-approved' label when a
+# component-specific codeowner approves (or dismisses) a PR.
+# This helps maintainers prioritize PRs that have codeowner sign-off.
+#
+# Only component-specific codeowners count — the catch-all @esphome/core
+# team is excluded so the label reflects domain-expert approval.
+
+name: Codeowner Approved Label
+
+on:
+  pull_request_review:
+    types: [submitted, dismissed]
+
+permissions:
+  pull-requests: write
+  contents: read
+
+jobs:
+  codeowner-approved:
+    name: Run
+    if: ${{ github.repository == 'esphome/esphome' }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Check codeowner approval and update label
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          script: |
+            const { fetchCodeowners, getEffectiveOwners } = require('./.github/scripts/codeowners.js');
+
+            const owner = context.repo.owner;
+            const repo = context.repo.repo;
+            const pr_number = context.payload.pull_request.number;
+            const LABEL_NAME = 'code-owner-approved';
+
+            console.log(`Processing PR #${pr_number} for codeowner approval label`);
+
+            try {
+              // Get the list of changed files in this PR (with pagination)
+              const prFiles = await github.paginate(
+                github.rest.pulls.listFiles,
+                {
+                  owner,
+                  repo,
+                  pull_number: pr_number
+                }
+              );
+
+              const changedFiles = prFiles.map(file => file.filename);
+              console.log(`Found ${changedFiles.length} changed files`);
+
+              if (changedFiles.length === 0) {
+                console.log('No changed files found, skipping');
+                return;
+              }
+
+              // Fetch and parse CODEOWNERS from base branch
+              const codeownersPatterns = await fetchCodeowners(
+                github, owner, repo,
+                context.payload.pull_request.base.sha
+              );
+
+              // Get effective owners using last-match-wins semantics
+              const effective = getEffectiveOwners(changedFiles, codeownersPatterns);
+
+              // Only keep individual component-specific codeowners (exclude teams)
+              const componentCodeowners = effective.users;
+
+              console.log(`Component-specific codeowners for changed files: ${Array.from(componentCodeowners).join(', ') || '(none)'}`);
+
+              if (componentCodeowners.size === 0) {
+                console.log('No component-specific codeowners found for changed files');
+                // Remove label if present since there are no component codeowners
+                try {
+                  await github.rest.issues.removeLabel({
+                    owner,
+                    repo,
+                    issue_number: pr_number,
+                    name: LABEL_NAME
+                  });
+                  console.log(`Removed '${LABEL_NAME}' label (no component codeowners)`);
+                } catch (error) {
+                  if (error.status !== 404) {
+                    console.log(`Failed to remove label: ${error.message}`);
+                  }
+                }
+                return;
+              }
+
+              // Get all reviews on the PR
+              const reviews = await github.paginate(
+                github.rest.pulls.listReviews,
+                {
+                  owner,
+                  repo,
+                  pull_number: pr_number
+                }
+              );
+
+              // Get the latest review per user (reviews are returned chronologically)
+              const latestReviewByUser = new Map();
+              for (const review of reviews) {
+                // Skip bot reviews and comment-only reviews
+                if (!review.user || review.state === 'COMMENTED') continue;
+                latestReviewByUser.set(review.user.login, review);
+              }
+
+              // Check if any component-specific codeowner has an active approval
+              let hasCodeownerApproval = false;
+              for (const [login, review] of latestReviewByUser) {
+                if (review.state === 'APPROVED' && componentCodeowners.has(login)) {
+                  console.log(`Codeowner '${login}' has approved`);
+                  hasCodeownerApproval = true;
+                  break;
+                }
+              }
+
+              // Get current labels to check if label is already present
+              const { data: currentLabels } = await github.rest.issues.listLabelsOnIssue({
+                owner,
+                repo,
+                issue_number: pr_number
+              });
+              const hasLabel = currentLabels.some(label => label.name === LABEL_NAME);
+
+              if (hasCodeownerApproval && !hasLabel) {
+                // Add the label
+                await github.rest.issues.addLabels({
+                  owner,
+                  repo,
+                  issue_number: pr_number,
+                  labels: [LABEL_NAME]
+                });
+                console.log(`Added '${LABEL_NAME}' label`);
+              } else if (!hasCodeownerApproval && hasLabel) {
+                // Remove the label
+                try {
+                  await github.rest.issues.removeLabel({
+                    owner,
+                    repo,
+                    issue_number: pr_number,
+                    name: LABEL_NAME
+                  });
+                  console.log(`Removed '${LABEL_NAME}' label`);
+                } catch (error) {
+                  if (error.status !== 404) {
+                    console.log(`Failed to remove label: ${error.message}`);
+                  }
+                }
+              } else {
+                console.log(`Label already ${hasLabel ? 'present' : 'absent'}, no change needed`);
+              }
+
+            } catch (error) {
+              console.log('Failed to process codeowner approval label:', error.message);
+              console.error(error);
+            }