Improve stale PR auto-labeling and management

Enhance stale PR management by auto-labeling PRs with no activity in the last 14 days and maintaining existing stale PR handling.

.github/workflows/stale_pr_close.yml

@@ -22,7 +22,7 @@ jobs:
             const now = new Date();
             const owner = context.repo.owner;
             const repo = context.repo.repo;
-            
+
             // --- When stale label is added, comment immediately ---
             if (context.eventName === "pull_request_target" && context.payload.action === "labeled") {
               const label = context.payload.label?.name;
@@ -37,19 +37,74 @@ jobs:
               }
               return;
             }
-            
-            // --- Scheduled run: check all stale PRs ---
+
+            // --- Scheduled run: fetch all open PRs ---
             const { data: prs } = await github.rest.pulls.list({
               owner,
               repo,
               state: "open",
               per_page: 100
             });
-            
+
             for (const pr of prs) {
-              const hasStale = pr.labels.some(l => l.name === "stale");
-              if (!hasStale) continue;
-              
+              const labels = pr.labels.map(l => l.name);
+              const hasStale = labels.includes("stale");
+              const hasKeepOpen = labels.includes("keep-open");
+
+              // -------------------------------------------------------
+              // NEW: Auto-label PRs with no activity in the last 14 days
+              // -------------------------------------------------------
+              if (!hasStale && !hasKeepOpen) {
+                // Find the most recent commit date
+                const { data: commits } = await github.rest.pulls.listCommits({
+                  owner,
+                  repo,
+                  pull_number: pr.number
+                });
+                const lastCommitDate = commits.length > 0
+                  ? new Date(commits[commits.length - 1].commit.author.date)
+                  : new Date(pr.created_at);
+
+                // Find the most recent non-bot comment date
+                const { data: comments } = await github.rest.issues.listComments({
+                  owner,
+                  repo,
+                  issue_number: pr.number,
+                  per_page: 100
+                });
+                const humanComments = comments.filter(c => c.user?.type !== "Bot");
+                const lastCommentDate = humanComments.length > 0
+                  ? new Date(humanComments[humanComments.length - 1].created_at)
+                  : null;
+
+                // Most recent activity across commits and comments
+                const lastActivityDate = lastCommentDate && lastCommentDate > lastCommitDate
+                  ? lastCommentDate
+                  : lastCommitDate;
+
+                const daysSinceActivity = (now - lastActivityDate) / (1000 * 60 * 60 * 24);
+
+                if (daysSinceActivity > 14) {
+                  await github.rest.issues.addLabels({
+                    owner,
+                    repo,
+                    issue_number: pr.number,
+                    labels: ["stale"]
+                  });
+                  // The pull_request_target labeled event will fire the comment automatically.
+                  // Skip further processing for this PR in this run.
+                  continue;
+                }
+
+                // Not stale, nothing else to do for this PR.
+                continue;
+              }
+
+              // -------------------------------------------------------
+              // EXISTING: Manage already-stale PRs
+              // -------------------------------------------------------
+              if (!hasStale) continue; // has keep-open but not stale — skip
+
               // Get timeline events to find when stale label was added
               const { data: events } = await github.rest.issues.listEvents({
                 owner,
@@ -57,27 +112,27 @@ jobs:
                 issue_number: pr.number,
                 per_page: 100
               });
-              
+
               // Find the most recent time the stale label was added
               const staleLabelEvents = events
                 .filter(e => e.event === "labeled" && e.label?.name === "stale")
                 .sort((a, b) => new Date(b.created_at) - new Date(a.created_at));
-              
+
               if (staleLabelEvents.length === 0) continue;
-              
+
               const staleLabelDate = new Date(staleLabelEvents[0].created_at);
               const daysSinceStale = (now - staleLabelDate) / (1000 * 60 * 60 * 24);
-              
+
               // Check for new commits since stale label was added
               const { data: commits } = await github.rest.pulls.listCommits({
                 owner,
                 repo,
                 pull_number: pr.number
               });
-              
+
               const lastCommitDate = new Date(commits[commits.length - 1].commit.author.date);
               const author = pr.user.login;
-              
+
               // If there are new commits after the stale label, remove it
               if (lastCommitDate > staleLabelDate) {
                 await github.rest.issues.removeLabel({