feat(triage): assign one accountable owner when a PR opens, and when deferring

.github/issue-owners.json

@@ -1,5 +1,5 @@
 {
-  "$comment": "Label-driven issue assignment map; areas are keyed on the existing issue label taxonomy. Assignment is a pure function of an issue's labels — no model output is involved. Owners need push access but do NOT need a CODEOWNERS entry; every candidate is re-checked against the collaborator API at write time, so adding a login here cannot grant access to someone who lacks it. Areas match in file order, first match wins. See docs/design/2026-08-07-issue-auto-assignment.md.",
+  "$comment": "Label-driven issue assignment map; areas are keyed on the existing issue label taxonomy. Assignment is a pure function of an issue's labels — no model output is involved. Owners need push access but do NOT need a CODEOWNERS entry; every candidate is re-checked against the collaborator API at write time, so adding a login here cannot grant access to someone who lacks it. Areas match in file order, first match wins. An area's optional paths list routes PR assignment (assign-pr-owner.mjs) by changed-file prefix, longest prefix wins; the core area's packages/core/ entry is the fallback for paths no module claims. Issue assignment ignores paths; module areas sit after core so label-based issue matching still resolves core first. See docs/design/2026-08-07-issue-auto-assignment.md.",
   "requireLabels": ["need-discussion"],
   "skipLabels": [
     "welcome-pr",
@@ -13,6 +13,7 @@
     {
       "name": "core",
       "labels": ["category/core", "scope/core"],
+      "paths": ["packages/core/"],
       "owners": [
         "wenshao",
         "yiliang114",
@@ -30,6 +31,59 @@
         "zjunothing",
         "ZijianZhang989"
       ]
+    },
+    {
+      "name": "core-skills",
+      "labels": ["scope/core"],
+      "paths": ["packages/core/src/skills/"],
+      "owners": ["wenshao"]
+    },
+    {
+      "name": "core-memory",
+      "labels": ["scope/core"],
+      "paths": ["packages/core/src/memory/"],
+      "owners": ["wenshao"]
+    },
+    {
+      "name": "core-goals",
+      "labels": ["scope/core"],
+      "paths": ["packages/core/src/goals/"],
+      "owners": ["qqqys"]
+    },
+    {
+      "name": "core-telemetry",
+      "labels": ["scope/core"],
+      "paths": ["packages/core/src/telemetry/"],
+      "owners": ["zjunothing"]
+    },
+    {
+      "name": "core-extension",
+      "labels": ["scope/core"],
+      "paths": ["packages/core/src/extension/"],
+      "owners": ["callmeYe"]
+    },
+    {
+      "name": "core-agents",
+      "labels": ["scope/core"],
+      "paths": ["packages/core/src/agents/"],
+      "owners": ["qqqys"]
+    },
+    {
+      "name": "core-config",
+      "labels": ["scope/core"],
+      "paths": ["packages/core/src/config/"],
+      "owners": ["qqqys"]
+    },
+    {
+      "name": "core-runtime",
+      "labels": ["scope/core"],
+      "paths": [
+        "packages/core/src/core/",
+        "packages/core/src/services/",
+        "packages/core/src/tools/",
+        "packages/core/src/utils/"
+      ],
+      "owners": ["yiliang114"]
     }
   ]
 }

.github/scripts/assign-issue-owner.mjs

@@ -20,6 +20,19 @@ function isStringArray(value) {
   return Array.isArray(value) && value.every((v) => typeof v === 'string');
 }
 
+// A changed-file prefix for assign-pr-owner.mjs: relative, no `//`, no
+// backslash, no `.`/`..` segments, and ending in `/` so startsWith cannot
+// leak into a sibling directory (packages/core matching packages/coredump/).
+function isPathPrefix(prefix) {
+  if (typeof prefix !== 'string' || prefix.length === 0) return false;
+  if (prefix.startsWith('/') || prefix.startsWith('./')) return false;
+  if (!prefix.endsWith('/')) return false;
+  if (prefix.includes('\\') || prefix.includes('//')) return false;
+  return !prefix
+    .split('/')
+    .some((segment) => segment === '.' || segment === '..');
+}
+
 export function loadPolicy(raw) {
   const policy = JSON.parse(raw);
   if (!policy || typeof policy !== 'object' || Array.isArray(policy)) {
@@ -74,6 +87,28 @@ export function loadPolicy(raw) {
       }
       seen.add(normalizedOwner);
     }
+    // A never-matching paths entry silently unroutes the area from PR
+    // assignment, so reject it here like other malformed config.
+    if (area.paths !== undefined && !Array.isArray(area.paths)) {
+      throw new Error(
+        `${OWNERS_FILE}: area ${area.name} paths must be an array`,
+      );
+    }
+    // An explicitly empty list can never route the area either, yet the
+    // entry loop below cannot catch it — reject it like the sibling
+    // labels/owners checks do.
+    if (Array.isArray(area.paths) && area.paths.length === 0) {
+      throw new Error(
+        `${OWNERS_FILE}: area ${area.name} paths must not be empty; omit paths for a label-only area`,
+      );
+    }
+    for (const prefix of area.paths ?? []) {
+      if (!isPathPrefix(prefix)) {
+        throw new Error(
+          `${OWNERS_FILE}: invalid paths entry in ${area.name}: ${JSON.stringify(prefix)}`,
+        );
+      }
+    }
   }
   return policy;
 }
@@ -151,7 +186,7 @@ function canWrite(repository, login) {
   }
 }
 
-function openIssueCount(repository, login) {
+export function openIssueCount(repository, login) {
   return Number(
     gh([
       'issue',

.github/scripts/assign-issue-owner.test.mjs

@@ -149,6 +149,43 @@ describe('assign-issue-owner: owner map', () => {
     broken.areas[0].owners = [42];
     assert.throws(() => loadPolicy(JSON.stringify(broken)), /invalid login/);
   });
+
+  it('rejects paths entries that could never route the area', () => {
+    // startsWith matching can never honour these spellings; accepting them
+    // would silently unroute the area from PR assignment forever.
+    for (const paths of [
+      ['./packages/core/'],
+      ['packages//core/'],
+      ['.github/../packages/core/'],
+      ['/packages/core/'],
+      ['packages/core'],
+      ['packages\\core/'],
+      [''],
+      [42],
+    ]) {
+      const broken = JSON.parse(ownersRaw);
+      broken.areas[0].paths = paths;
+      assert.throws(
+        () => loadPolicy(JSON.stringify(broken)),
+        /invalid paths entry/,
+      );
+    }
+
+    const notArray = JSON.parse(ownersRaw);
+    notArray.areas[0].paths = 'packages/core/';
+    assert.throws(
+      () => loadPolicy(JSON.stringify(notArray)),
+      /paths must be an array/,
+    );
+
+    // An explicitly empty list can never route the area either.
+    const emptyPaths = JSON.parse(ownersRaw);
+    emptyPaths.areas[0].paths = [];
+    assert.throws(
+      () => loadPolicy(JSON.stringify(emptyPaths)),
+      /paths must not be empty/,
+    );
+  });
 });
 
 describe('assign-issue-owner: skip policy', () => {