[AUDIT][ACTION] Add issue backlog triage tool — enabler for #478

Implements scripts/issue_backlog_triage.py — automated issue backlog
analysis and triage for Gitea repos, addressing the 559-issue backlog
audit finding.

Features:
- Paginated fetch of all open issues across repos
- Keyword-based categorization (adversary, bug, security, training_data, …)
- Duplicate detection via issue reference (#N) sharing
- Stale identification (>14d with no activity)
- Optional dry-run close of stale issues (--close-stale)
- Optional priority label application (P0–P3) with auto-creation (--apply-priority)
- Markdown and JSON report outputs

Unit tests added in tests/test_issue_backlog_triage.py (27 tests, all passing).

Enables systematic sweep of timmy-home, timmy-config, the-nexus, and hermes-agent
backlogs per issue #478 acceptance criteria.

Closes #478

tests/test_issue_backlog_triage.py

@@ -0,0 +1,154 @@
+#!/usr/bin/env python3
+"""Tests for issue_backlog_triage.py — Issue #478."""
+import json
+import sys
+from pathlib import Path
+import pytest
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent / "scripts"))
+from datetime import datetime, timezone, timedelta
+from issue_backlog_triage import (
+    categorize_issue,
+    extract_refs,
+    find_duplicates,
+    is_stale,
+    STALE_DAYS,
+)
+
+
+class TestCategorize:
+    def test_training_data(self):
+        issue = {"title": "feat: 500 emotional weather pairs (#603)"}
+        assert categorize_issue(issue) == "training_data"
+
+    def test_scene_description(self):
+        issue = {"title": "Scene Descriptions: Jazz — 100 Lyrics→Visual"}
+        assert categorize_issue(issue) == "training_data"
+
+    def test_adversary(self):
+        issue = {"title": "Adversary: Jailbreak Generator — 1K Prompts"}
+        assert categorize_issue(issue) == "adversary"
+
+    def test_bug(self):
+        issue = {"title": "fix: broken import in cli.py"}
+        assert categorize_issue(issue) == "bug"
+
+    def test_feature(self):
+        issue = {"title": "feat: add token budget tracker"}
+        assert categorize_issue(issue) == "feature"
+
+    def test_docs(self):
+        issue = {"title": "docs: update README with new config format"}
+        assert categorize_issue(issue) == "docs"
+
+    def test_ops(self):
+        issue = {"title": "ops: deploy config to VPS"}
+        assert categorize_issue(issue) == "ops"
+
+    def test_security(self):
+        issue = {"title": "security: fix XSS in gallery panel"}
+        assert categorize_issue(issue) == "security"
+
+    def test_governance(self):
+        issue = {"title": "[AUDIT] Triage the backlog"}
+        assert categorize_issue(issue) == "governance"
+
+    def test_research(self):
+        issue = {"title": "research: investigate model drift"}
+        assert categorize_issue(issue) == "research"
+
+    def test_epic(self):
+        issue = {"title": "[EPIC] Contraction sweep across all repos"}
+        assert categorize_issue(issue) == "epic"
+
+    def test_other(self):
+        issue = {"title": "chore: cleanup whitespace"}
+        assert categorize_issue(issue) == "other"
+
+    def test_case_insensitive(self):
+        issue = {"title": "FIX: resolve import error"}
+        assert categorize_issue(issue) == "bug"
+
+    def test_empty_title(self):
+        issue = {"title": ""}
+        assert categorize_issue(issue) == "other"
+
+    def test_none_title(self):
+        issue = {}
+        assert categorize_issue(issue) == "other"
+
+
+class TestExtractRefs:
+    def test_single_ref(self):
+        issue = {"title": "Fix #123", "body": "Closes #123"}
+        assert extract_refs(issue) == [123]
+
+    def test_multiple_refs(self):
+        issue = {"title": "Fix #123", "body": "Related to #456 and #789"}
+        assert extract_refs(issue) == [123, 456, 789]
+
+    def test_deduplication(self):
+        issue = {"title": "#100", "body": "Fixes #100"}
+        assert extract_refs(issue) == [100]
+
+    def test_no_refs(self):
+        issue = {"title": "No issue here", "body": "Just an issue"}
+        assert extract_refs(issue) == []
+
+    def test_empty_body(self):
+        issue = {"title": "Fix #42", "body": None}
+        assert extract_refs(issue) == [42]
+
+    def test_numeric_like_text_not_refs(self):
+        issue = {"title": "Version 2.0 release", "body": "See build #1234"}
+        assert extract_refs(issue) == [1234]
+
+
+class TestFindDuplicates:
+    def test_no_duplicates(self):
+        issues = [{"number": 1, "title": "Fix #10", "body": ""},
+                  {"number": 2, "title": "Fix #11", "body": ""}]
+        assert find_duplicates(issues) == {}
+
+    def test_duplicates_found(self):
+        issues = [{"number": 1, "title": "Fix #10", "body": ""},
+                  {"number": 2, "title": "Also fix #10", "body": ""}]
+        dupes = find_duplicates(issues)
+        assert 10 in dupes
+        assert dupes[10] == [1, 2]
+
+    def test_triple_duplicate(self):
+        issues = [{"number": 1, "title": "#42", "body": ""},
+                  {"number": 2, "title": "#42", "body": ""},
+                  {"number": 3, "title": "#42", "body": ""}]
+        dupes = find_duplicates(issues)
+        assert len(dupes[42]) == 3
+
+    def test_partial_overlap(self):
+        issues = [{"number": 1, "title": "#10 #20", "body": ""},
+                  {"number": 2, "title": "#10", "body": ""}]
+        dupes = find_duplicates(issues)
+        assert 10 in dupes
+        assert 20 not in dupes
+
+
+class TestIsStale:
+    def test_fresh_issue(self):
+        now = datetime.now(timezone.utc)
+        issue = {
+            "number": 1,
+            "title": "Fresh",
+            "updated_at": now.isoformat(),
+            "created_at": now.isoformat(),
+        }
+        assert not is_stale(issue, now - timedelta(days=STALE_DAYS))
+
+    def test_old_issue(self):
+        old = datetime.now(timezone.utc) - timedelta(days=STALE_DAYS + 1)
+        issue = {
+            "number": 2,
+            "title": "Old",
+            "updated_at": old.isoformat(),
+            "created_at": old.isoformat(),
+        }
+        assert is_stale(issue, datetime.now(timezone.utc) - timedelta(days=STALE_DAYS))