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/api/test_models_validators.py

@@ -0,0 +1,73 @@
+import pytest
+from unittest.mock import patch
+from api.models.anthropic import MessagesRequest, TokenCountRequest, Message
+from config.settings import Settings
+
+
+@pytest.fixture
+def mock_settings():
+    settings = Settings()
+    settings.model = "target-model-from-settings"
+    return settings
+
+
+def test_messages_request_map_model_claude_to_default(mock_settings):
+    with patch("api.models.anthropic.get_settings", return_value=mock_settings):
+        request = MessagesRequest(
+            model="claude-3-opus",
+            max_tokens=100,
+            messages=[Message(role="user", content="hello")],
+        )
+
+        assert request.model == "target-model-from-settings"
+        assert request.original_model == "claude-3-opus"
+
+
+def test_messages_request_map_model_non_claude_unchanged(mock_settings):
+    with patch("api.models.anthropic.get_settings", return_value=mock_settings):
+        request = MessagesRequest(
+            model="gpt-4",
+            max_tokens=100,
+            messages=[Message(role="user", content="hello")],
+        )
+
+        # normalize_model_name returns original if not Claude
+        assert request.model == "gpt-4"
+
+
+def test_messages_request_map_model_with_provider_prefix(mock_settings):
+    with patch("api.models.anthropic.get_settings", return_value=mock_settings):
+        request = MessagesRequest(
+            model="anthropic/claude-3-haiku",
+            max_tokens=100,
+            messages=[Message(role="user", content="hello")],
+        )
+
+        assert request.model == "target-model-from-settings"
+
+
+def test_token_count_request_model_validation(mock_settings):
+    with patch("api.models.anthropic.get_settings", return_value=mock_settings):
+        request = TokenCountRequest(
+            model="claude-3-sonnet", messages=[Message(role="user", content="hello")]
+        )
+
+        assert request.model == "target-model-from-settings"
+
+
+def test_messages_request_model_mapping_logs(mock_settings):
+    with (
+        patch("api.models.anthropic.get_settings", return_value=mock_settings),
+        patch("api.models.anthropic.logger.debug") as mock_log,
+    ):
+        MessagesRequest(
+            model="claude-2.1",
+            max_tokens=100,
+            messages=[Message(role="user", content="hello")],
+        )
+
+        mock_log.assert_called()
+        args = mock_log.call_args[0][0]
+        assert "MODEL MAPPING" in args
+        assert "claude-2.1" in args
+        assert "target-model-from-settings" in args