feat(canvas): Custom extractor components, migrator, and MCP spec tools

Canvas Components:
- CustomExtractorNode.tsx: Node for custom Python extractors
- CustomExtractorPanel.tsx: Configuration panel for custom extractors
- ConnectionStatusIndicator.tsx: WebSocket status display
- atomizer-spec.ts: TypeScript types for AtomizerSpec v2.0

Config:
- migrator.py: Legacy config to AtomizerSpec v2.0 migration
- Updated __init__.py exports for config and extractors

MCP Tools:
- spec.ts: MCP tools for spec manipulation
- index.ts: Tool registration updates

optimization_engine/config/__init__.py

@@ -9,6 +9,7 @@ Modules:
 - builder: OptimizationConfigBuilder for creating configs
 - setup_wizard: Interactive configuration setup
 - capability_matcher: Match capabilities to requirements
+- spec_models: AtomizerSpec v2.0 Pydantic models (unified configuration)
 """
 
 # Lazy imports to avoid circular dependencies
@@ -31,6 +32,27 @@ def __getattr__(name):
     elif name == 'TemplateLoader':
         from .template_loader import TemplateLoader
         return TemplateLoader
+    elif name == 'AtomizerSpec':
+        from .spec_models import AtomizerSpec
+        return AtomizerSpec
+    elif name == 'SpecValidator':
+        from .spec_validator import SpecValidator
+        return SpecValidator
+    elif name == 'SpecValidationError':
+        from .spec_validator import SpecValidationError
+        return SpecValidationError
+    elif name == 'validate_spec':
+        from .spec_validator import validate_spec
+        return validate_spec
+    elif name == 'SpecMigrator':
+        from .migrator import SpecMigrator
+        return SpecMigrator
+    elif name == 'migrate_config':
+        from .migrator import migrate_config
+        return migrate_config
+    elif name == 'migrate_config_file':
+        from .migrator import migrate_config_file
+        return migrate_config_file
     raise AttributeError(f"module 'optimization_engine.config' has no attribute '{name}'")
 
 __all__ = [
@@ -40,4 +62,11 @@ __all__ = [
     'SetupWizard',
     'CapabilityMatcher',
     'TemplateLoader',
+    'AtomizerSpec',
+    'SpecValidator',
+    'SpecValidationError',
+    'validate_spec',
+    'SpecMigrator',
+    'migrate_config',
+    'migrate_config_file',
 ]