hive-forge: flag stale-branches merge outcome as unknown when the PR fetch is truncated

claude-plugins/plugins/base/skills/forge-triage/SKILL.md

@@ -33,7 +33,10 @@ dimension directly.
   heads of open PRs) and reports each one's merge outcome (PR merged /
   closed unmerged / no PR at all) — squash-merge ancestry can't tell
   those apart, so don't delete a stale branch on the age alone; check
-  the verdict first.
+  the verdict first. On a repo with enough PRs to exceed the verb's own
+  page cap, an old branch's outcome may come back "unknown" instead of
+  a verdict — that's not the same claim as "no PR", treat it as
+  "can't tell, don't delete" too.
 
 ## Using them as a sweep
 

hive-forge/src/verbs/lint.rs

@@ -289,6 +289,12 @@ fn run_stale_branches(client: &Client, args: StaleBranchesArgs) -> Result<()> {
     // hyperhive squash-merges, a merged branch's tip is never an
     // ancestor of main, so ancestry can't tell these apart; this is the
     // only signal that can.
+    // Whether the walk below hit `MAX_PAGES` without ever seeing a
+    // short page — i.e. there are more PRs than the cap fetched, so
+    // `latest_pr_by_head` is missing an unknown number of the oldest
+    // ones. Distinct from "no PR was found": that's a claim this walk
+    // can only make honestly when it actually saw everything.
+    let mut prs_truncated = false;
     let mut prs = Vec::new();
     for page in 1..=MAX_PAGES {
         let query = RepoListPullRequestsQuery {
@@ -306,6 +312,9 @@ fn run_stale_branches(client: &Client, args: StaleBranchesArgs) -> Result<()> {
         if short {
             break;
         }
+        if page == MAX_PAGES {
+            prs_truncated = true;
+        }
     }
     let mut active_heads: std::collections::HashSet<String> = std::collections::HashSet::new();
     // Highest-numbered (most recent) PR per head branch, in case a
@@ -343,14 +352,20 @@ fn run_stale_branches(client: &Client, args: StaleBranchesArgs) -> Result<()> {
         if age_days >= args.days {
             // A branch surviving to here can only have a *closed* PR
             // (an open one would already be in `active_heads`), so
-            // `merged` is unambiguous when a PR exists at all.
+            // `merged` is unambiguous when a PR exists at all. But
+            // "no PR found" is only true when the PR walk above wasn't
+            // truncated — otherwise this branch's PR may simply be
+            // older than the page cap reached, and reporting "no PR"
+            // would misrepresent an unknown as a verified negative.
             let pr = latest_pr_by_head.get(branch_name);
+            let outcome_unknown = pr.is_none() && prs_truncated;
             stale.push(json!({
                 "name": branch_name,
                 "last_commit": rfc3339(Some(ts)),
                 "age_days": age_days,
                 "pr": pr.and_then(|p| p.number),
                 "merged": pr.and_then(|p| p.merged),
+                "outcome_unknown": outcome_unknown,
             }));
         }
     }
@@ -360,9 +375,13 @@ fn run_stale_branches(client: &Client, args: StaleBranchesArgs) -> Result<()> {
         let verdict = match (
             it.get("pr").and_then(Value::as_i64),
             it.get("merged").and_then(Value::as_bool),
+            it.get("outcome_unknown")
+                .and_then(Value::as_bool)
+                .unwrap_or(false),
         ) {
-            (Some(pr), Some(true)) => format!("PR #{pr} merged"),
+            (Some(pr), Some(true), _) => format!("PR #{pr} merged"),
-            (Some(pr), Some(false)) => format!("PR #{pr} closed, not merged"),
+            (Some(pr), Some(false), _) => format!("PR #{pr} closed, not merged"),
+            (_, _, true) => "unknown (PR history too large to fully scan)".to_string(),
             _ => "no PR".to_string(),
         };
         format!("{name} ({age}d) — {verdict}")