refactor: improve config loader validation with Pydantic schemas

- Replace manual field type validation with Pydantic model schemas
- Add pydantic>=2.0 as core dependency
- Fix sync wrapper in decorator to properly handle rate limiting
- Update pyright settings for stricter type checking
- Fix repository URL in pyproject.toml
- Remove unused main.py
- Update test assertions for new validation error format

tests/test_config_loader.py

@@ -365,7 +365,7 @@ class TestConfigLoaderValidation:
             "FASTAPI_TRAFFIC_RATE_LIMIT_ALGORITHM": "invalid_algorithm",
         }
 
-        with pytest.raises(ConfigurationError, match="Cannot parse value"):
+        with pytest.raises(ConfigurationError):
             loader.load_rate_limit_config_from_env(env_vars)
 
     def test_invalid_int_value(self, loader: ConfigLoader) -> None:
@@ -374,7 +374,7 @@ class TestConfigLoaderValidation:
             "FASTAPI_TRAFFIC_RATE_LIMIT_LIMIT": "not_a_number",
         }
 
-        with pytest.raises(ConfigurationError, match="Cannot parse value"):
+        with pytest.raises(ConfigurationError):
             loader.load_rate_limit_config_from_env(env_vars)
 
     def test_invalid_float_value(self, loader: ConfigLoader) -> None:
@@ -384,7 +384,7 @@ class TestConfigLoaderValidation:
             "FASTAPI_TRAFFIC_RATE_LIMIT_WINDOW_SIZE": "not_a_float",
         }
 
-        with pytest.raises(ConfigurationError, match="Cannot parse value"):
+        with pytest.raises(ConfigurationError):
             loader.load_rate_limit_config_from_env(env_vars)
 
     def test_unknown_field(self, loader: ConfigLoader, temp_dir: Path) -> None:
@@ -411,7 +411,7 @@ class TestConfigLoaderValidation:
         config_data = {"limit": "not_an_int"}
         json_file.write_text(json.dumps(config_data))
 
-        with pytest.raises(ConfigurationError, match="Cannot parse value"):
+        with pytest.raises(ConfigurationError):
             loader.load_rate_limit_config_from_json(json_file)
 
     def test_bool_parsing_variations(self, loader: ConfigLoader) -> None: