refactor: modernize code quality tooling with Ruff

- Replace black, isort, and flake8 with Ruff (all-in-one linter and formatter)
- Add comprehensive pyproject.toml configuration
- Simplify Makefile code quality targets
- Configure exclusions for venv/.venv in pyproject.toml
- Auto-fix 1,359 linting issues across codebase

Benefits:
- Much faster builds (Ruff is written in Rust)
- Single tool replaces multiple tools
- More comprehensive rule set (UP, B, C4, SIM, PIE, RET, Q)
- All configuration centralized in pyproject.toml
- Better import sorting and formatting consistency

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

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

app/exceptions/error_renderer.py

@@ -5,9 +5,10 @@ Error Page Renderer
 Renders context-aware error pages using Jinja2 templates.
 Handles fallback logic and context-specific customization.
 """
+
 import logging
 from pathlib import Path
-from typing import Any, Dict, Optional
+from typing import Any
 
 from fastapi import Request
 from fastapi.responses import HTMLResponse
@@ -60,7 +61,7 @@ class ErrorPageRenderer:
         status_code: int,
         error_code: str,
         message: str,
-        details: Optional[Dict[str, Any]] = None,
+        details: dict[str, Any] | None = None,
         show_debug: bool = False,
     ) -> HTMLResponse:
         """
@@ -190,9 +191,9 @@ class ErrorPageRenderer:
         status_code: int,
         error_code: str,
         message: str,
-        details: Optional[Dict[str, Any]],
+        details: dict[str, Any] | None,
         show_debug: bool,
-    ) -> Dict[str, Any]:
+    ) -> dict[str, Any]:
         """Prepare data dictionary for error template."""
         # Get friendly status name
         status_name = ErrorPageRenderer.STATUS_CODE_NAMES.get(
@@ -229,7 +230,7 @@ class ErrorPageRenderer:
     @staticmethod
     def _get_context_data(
         request: Request, context_type: RequestContext
-    ) -> Dict[str, Any]:
+    ) -> dict[str, Any]:
         """Get context-specific data for error templates."""
         data = {}