Phase 7: Directory restructuring (messaging/ and tests/)

- Create messaging/platforms/ (base, discord, telegram, factory)
- Create messaging/rendering/ (discord_markdown, telegram_markdown)
- Create messaging/trees/ (data, repository, processor, queue_manager)
- Organize tests/ into api/, providers/, messaging/, cli/, config/
- Add backward-compatible re-exports at old locations
- Update handler.py and test_messaging_factory.py imports
- Fix Telegram type hints for TELEGRAM_AVAILABLE=False case
- Fix Python 3 except syntax in discord_markdown

Co-authored-by: Ali Khokhar <alishahryar2@gmail.com>

tests/messaging/test_messaging_factory.py

@@ -0,0 +1,73 @@
+"""Tests for messaging platform factory."""
+
+from unittest.mock import patch, MagicMock
+
+from messaging.factory import create_messaging_platform
+
+
+class TestCreateMessagingPlatform:
+    """Tests for create_messaging_platform factory function."""
+
+    def test_telegram_with_token(self):
+        """Create Telegram platform when bot_token is provided."""
+        mock_platform = MagicMock()
+        with patch("messaging.platforms.telegram.TELEGRAM_AVAILABLE", True):
+            with patch(
+                "messaging.platforms.telegram.TelegramPlatform",
+                return_value=mock_platform,
+            ):
+                result = create_messaging_platform(
+                    "telegram",
+                    bot_token="test_token",
+                    allowed_user_id="12345",
+                )
+
+        assert result is mock_platform
+
+    def test_telegram_without_token(self):
+        """Return None when no bot_token for Telegram."""
+        result = create_messaging_platform("telegram")
+        assert result is None
+
+    def test_telegram_empty_token(self):
+        """Return None when bot_token is empty string."""
+        result = create_messaging_platform("telegram", bot_token="")
+        assert result is None
+
+    def test_discord_with_token(self):
+        """Create Discord platform when discord_bot_token is provided."""
+        mock_platform = MagicMock()
+        with patch("messaging.platforms.discord.DISCORD_AVAILABLE", True):
+            with patch(
+                "messaging.platforms.discord.DiscordPlatform",
+                return_value=mock_platform,
+            ):
+                result = create_messaging_platform(
+                    "discord",
+                    discord_bot_token="test_token",
+                    allowed_discord_channels="123,456",
+                )
+
+        assert result is mock_platform
+
+    def test_discord_without_token(self):
+        """Return None when no discord_bot_token for Discord."""
+        result = create_messaging_platform("discord")
+        assert result is None
+
+    def test_discord_empty_token(self):
+        """Return None when discord_bot_token is empty string."""
+        result = create_messaging_platform(
+            "discord", discord_bot_token="", allowed_discord_channels="123"
+        )
+        assert result is None
+
+    def test_unknown_platform(self):
+        """Return None for unknown platform types."""
+        result = create_messaging_platform("slack")
+        assert result is None
+
+    def test_unknown_platform_with_kwargs(self):
+        """Return None for unknown platform even with kwargs."""
+        result = create_messaging_platform("slack", bot_token="token")
+        assert result is None