test: add unit tests for 8 untested modules (batch 3) (#191)

* test: add unit tests for 8 untested modules (batch 3)

New test files (143 tests total):
- tools/debug_helpers.py: DebugSession enable/disable, log, save, session info
- tools/skills_guard.py: scan_file, scan_skill, trust levels, install policy, structural checks
- tools/skills_sync.py: manifest read/write, skill discovery, sync logic
- gateway/sticker_cache.py: cache CRUD, sticker injection text builders
- gateway/channel_directory.py: channel resolution, display formatting, session building
- gateway/hooks.py: hook discovery, sync/async emit, wildcard matching
- gateway/mirror.py: session lookup, JSONL append, mirror_to_session
- honcho_integration/client.py: config from env/file, session name resolution, linked workspaces

Also documents a gap in skills_guard: multi-word prompt injection
variants like "ignore all prior instructions" bypass the regex scanner.

* test: strengthen sticker injection tests with exact format assertions

Replace loose "contains" checks with exact output matching for
build_sticker_injection and build_animated_sticker_injection.
Add edge cases: set_name without emoji, empty description, empty emoji.

* test: remove skills_guard gap-documenting test to avoid conflict with fix PR

tests/gateway/test_mirror.py

@@ -0,0 +1,162 @@
+"""Tests for gateway/mirror.py — session mirroring."""
+
+import json
+from pathlib import Path
+from unittest.mock import patch, MagicMock
+
+import gateway.mirror as mirror_mod
+from gateway.mirror import (
+    mirror_to_session,
+    _find_session_id,
+    _append_to_jsonl,
+)
+
+
+def _setup_sessions(tmp_path, sessions_data):
+    """Helper to write a fake sessions.json and patch module-level paths."""
+    sessions_dir = tmp_path / "sessions"
+    sessions_dir.mkdir(parents=True, exist_ok=True)
+    index_file = sessions_dir / "sessions.json"
+    index_file.write_text(json.dumps(sessions_data))
+    return sessions_dir, index_file
+
+
+class TestFindSessionId:
+    def test_finds_matching_session(self, tmp_path):
+        sessions_dir, index_file = _setup_sessions(tmp_path, {
+            "agent:main:telegram:dm": {
+                "session_id": "sess_abc",
+                "origin": {"platform": "telegram", "chat_id": "12345"},
+                "updated_at": "2026-01-01T00:00:00",
+            }
+        })
+
+        with patch.object(mirror_mod, "_SESSIONS_DIR", sessions_dir), \
+             patch.object(mirror_mod, "_SESSIONS_INDEX", index_file):
+            result = _find_session_id("telegram", "12345")
+
+        assert result == "sess_abc"
+
+    def test_returns_most_recent(self, tmp_path):
+        sessions_dir, index_file = _setup_sessions(tmp_path, {
+            "old": {
+                "session_id": "sess_old",
+                "origin": {"platform": "telegram", "chat_id": "12345"},
+                "updated_at": "2026-01-01T00:00:00",
+            },
+            "new": {
+                "session_id": "sess_new",
+                "origin": {"platform": "telegram", "chat_id": "12345"},
+                "updated_at": "2026-02-01T00:00:00",
+            },
+        })
+
+        with patch.object(mirror_mod, "_SESSIONS_DIR", sessions_dir), \
+             patch.object(mirror_mod, "_SESSIONS_INDEX", index_file):
+            result = _find_session_id("telegram", "12345")
+
+        assert result == "sess_new"
+
+    def test_no_match_returns_none(self, tmp_path):
+        sessions_dir, index_file = _setup_sessions(tmp_path, {
+            "sess": {
+                "session_id": "sess_1",
+                "origin": {"platform": "discord", "chat_id": "999"},
+                "updated_at": "2026-01-01T00:00:00",
+            }
+        })
+
+        with patch.object(mirror_mod, "_SESSIONS_INDEX", index_file):
+            result = _find_session_id("telegram", "12345")
+
+        assert result is None
+
+    def test_missing_sessions_file(self, tmp_path):
+        with patch.object(mirror_mod, "_SESSIONS_INDEX", tmp_path / "nope.json"):
+            result = _find_session_id("telegram", "12345")
+
+        assert result is None
+
+    def test_platform_case_insensitive(self, tmp_path):
+        sessions_dir, index_file = _setup_sessions(tmp_path, {
+            "s1": {
+                "session_id": "sess_1",
+                "origin": {"platform": "Telegram", "chat_id": "123"},
+                "updated_at": "2026-01-01T00:00:00",
+            }
+        })
+
+        with patch.object(mirror_mod, "_SESSIONS_INDEX", index_file):
+            result = _find_session_id("telegram", "123")
+
+        assert result == "sess_1"
+
+
+class TestAppendToJsonl:
+    def test_appends_message(self, tmp_path):
+        sessions_dir = tmp_path / "sessions"
+        sessions_dir.mkdir()
+
+        with patch.object(mirror_mod, "_SESSIONS_DIR", sessions_dir):
+            _append_to_jsonl("sess_1", {"role": "assistant", "content": "Hello"})
+
+        transcript = sessions_dir / "sess_1.jsonl"
+        lines = transcript.read_text().strip().splitlines()
+        assert len(lines) == 1
+        msg = json.loads(lines[0])
+        assert msg["role"] == "assistant"
+        assert msg["content"] == "Hello"
+
+    def test_appends_multiple_messages(self, tmp_path):
+        sessions_dir = tmp_path / "sessions"
+        sessions_dir.mkdir()
+
+        with patch.object(mirror_mod, "_SESSIONS_DIR", sessions_dir):
+            _append_to_jsonl("sess_1", {"role": "assistant", "content": "msg1"})
+            _append_to_jsonl("sess_1", {"role": "assistant", "content": "msg2"})
+
+        transcript = sessions_dir / "sess_1.jsonl"
+        lines = transcript.read_text().strip().splitlines()
+        assert len(lines) == 2
+
+
+class TestMirrorToSession:
+    def test_successful_mirror(self, tmp_path):
+        sessions_dir, index_file = _setup_sessions(tmp_path, {
+            "s1": {
+                "session_id": "sess_abc",
+                "origin": {"platform": "telegram", "chat_id": "12345"},
+                "updated_at": "2026-01-01T00:00:00",
+            }
+        })
+
+        with patch.object(mirror_mod, "_SESSIONS_DIR", sessions_dir), \
+             patch.object(mirror_mod, "_SESSIONS_INDEX", index_file), \
+             patch("gateway.mirror._append_to_sqlite"):
+            result = mirror_to_session("telegram", "12345", "Hello!", source_label="cli")
+
+        assert result is True
+
+        # Check JSONL was written
+        transcript = sessions_dir / "sess_abc.jsonl"
+        assert transcript.exists()
+        msg = json.loads(transcript.read_text().strip())
+        assert msg["content"] == "Hello!"
+        assert msg["role"] == "assistant"
+        assert msg["mirror"] is True
+        assert msg["mirror_source"] == "cli"
+
+    def test_no_matching_session(self, tmp_path):
+        sessions_dir, index_file = _setup_sessions(tmp_path, {})
+
+        with patch.object(mirror_mod, "_SESSIONS_DIR", sessions_dir), \
+             patch.object(mirror_mod, "_SESSIONS_INDEX", index_file):
+            result = mirror_to_session("telegram", "99999", "Hello!")
+
+        assert result is False
+
+    def test_error_returns_false(self, tmp_path):
+        with patch("gateway.mirror._find_session_id", side_effect=Exception("boom")):
+            result = mirror_to_session("telegram", "123", "msg")
+
+        assert result is False