refactor: split architecture rules into domain-specific files

Split the monolithic .architecture-rules.yaml (1700+ lines) into focused
domain-specific files in .architecture-rules/ directory:

- _main.yaml: Core config, principles, ignore patterns, severity levels
- api.yaml: API endpoint rules (API-001 to API-005)
- service.yaml: Service layer rules (SVC-001 to SVC-007)
- model.yaml: Model rules (MDL-001 to MDL-004)
- exception.yaml: Exception handling rules (EXC-001 to EXC-005)
- naming.yaml: Naming convention rules (NAM-001 to NAM-005)
- auth.yaml: Auth and multi-tenancy rules (AUTH-*, MT-*)
- middleware.yaml: Middleware rules (MDW-001 to MDW-002)
- frontend.yaml: Frontend rules (JS-*, TPL-*, FE-*, CSS-*)
- language.yaml: Language/i18n rules (LANG-001 to LANG-010)
- quality.yaml: Code quality rules (QUAL-001 to QUAL-003)

Also creates scripts/validators/ module with base classes for future
modular validator extraction.

The validate_architecture.py loader now auto-detects and merges split
YAML files while maintaining backward compatibility with single file mode.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.architecture-rules/exception.yaml

@@ -0,0 +1,66 @@
+# Architecture Rules - Exception Handling Rules
+# Rules for exception handling across the application
+
+exception_rules:
+
+  - id: "EXC-001"
+    name: "Define custom exceptions in exceptions module"
+    severity: "warning"
+    description: |
+      Create domain-specific exceptions in app/exceptions/ for better
+      error handling and clarity.
+    pattern:
+      file_pattern: "app/exceptions/**/*.py"
+      encouraged_structure: |
+        class VendorError(Exception):
+            """Base exception for vendor-related errors"""
+            pass
+
+  - id: "EXC-002"
+    name: "Never use bare except"
+    severity: "error"
+    description: |
+      Always specify exception types. Bare except catches everything including
+      KeyboardInterrupt and SystemExit.
+    pattern:
+      file_pattern: "**/*.py"
+      anti_patterns:
+        - "except:"
+        - "except\\s*:"
+
+  - id: "EXC-003"
+    name: "Log all exceptions with context"
+    severity: "warning"
+    description: |
+      When catching exceptions, log them with context and stack trace.
+    pattern:
+      file_pattern: "app/services/**/*.py"
+      encouraged_patterns:
+        - "logger.error"
+        - "exc_info=True"
+
+  - id: "EXC-004"
+    name: "Domain exceptions must inherit from WizamartException"
+    severity: "error"
+    description: |
+      All custom domain exceptions must inherit from WizamartException (or its
+      subclasses like ResourceNotFoundException, ValidationException, etc.).
+      This ensures the global exception handler catches and converts them properly.
+    pattern:
+      file_pattern: "app/exceptions/**/*.py"
+      required_base_class: "WizamartException"
+      example_good: |
+        class VendorNotFoundException(ResourceNotFoundException):
+            def __init__(self, vendor_code: str):
+                super().__init__(resource_type="Vendor", identifier=vendor_code)
+
+  - id: "EXC-005"
+    name: "Exception handler must be registered"
+    severity: "error"
+    description: |
+      The global exception handler must be set up in app initialization to
+      catch WizamartException and convert to HTTP responses.
+    pattern:
+      file_pattern: "app/main.py"
+      required_patterns:
+        - "setup_exception_handlers"