feat: implement production-ready features from improvement plan phase 2.5 & 2.6

Phase 2.5: Fix Foundation (CRITICAL)
- Fixed 4 failing tests by adding cache attribute to mock_client fixture
- Created comprehensive cache tests for Pages endpoint (test_pages_cache.py)
- Added missing dependencies: pydantic[email] and aiohttp to core requirements
- Updated requirements.txt with proper dependency versions
- Achieved 82.67% test coverage with 454 passing tests

Phase 2.6: Production Essentials
- Implemented structured logging (wikijs/logging.py)
  * JSON and text log formatters
  * Configurable log levels and output destinations
  * Integration with client operations

- Implemented metrics and telemetry (wikijs/metrics.py)
  * Request tracking with duration, status codes, errors
  * Latency percentiles (min, max, avg, p50, p95, p99)
  * Error rate calculation
  * Thread-safe metrics collection

- Implemented rate limiting (wikijs/ratelimit.py)
  * Token bucket algorithm for request throttling
  * Per-endpoint rate limiting support
  * Configurable timeout handling
  * Burst capacity management

- Created SECURITY.md policy
  * Vulnerability reporting procedures
  * Security best practices
  * Response timelines
  * Supported versions

Documentation
- Added comprehensive logging guide (docs/logging.md)
- Added metrics and telemetry guide (docs/metrics.md)
- Added rate limiting guide (docs/rate_limiting.md)
- Updated README.md with production features section
- Updated IMPROVEMENT_PLAN_2.md with completed checkboxes

Testing
- Created test suite for logging (tests/test_logging.py)
- Created test suite for metrics (tests/test_metrics.py)
- Created test suite for rate limiting (tests/test_ratelimit.py)
- All 454 tests passing
- Test coverage: 82.67%

Breaking Changes: None
Dependencies Added: pydantic[email], email-validator, dnspython

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

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

wikijs/logging.py

@@ -0,0 +1,84 @@
+"""Logging configuration for wikijs-python-sdk."""
+import logging
+import json
+import sys
+from typing import Any, Dict, Optional
+from datetime import datetime
+
+
+class JSONFormatter(logging.Formatter):
+    """JSON formatter for structured logging."""
+
+    def format(self, record: logging.LogRecord) -> str:
+        """Format log record as JSON.
+
+        Args:
+            record: The log record to format
+
+        Returns:
+            JSON formatted log string
+        """
+        log_data: Dict[str, Any] = {
+            "timestamp": datetime.utcnow().isoformat(),
+            "level": record.levelname,
+            "logger": record.name,
+            "message": record.getMessage(),
+            "module": record.module,
+            "function": record.funcName,
+            "line": record.lineno,
+        }
+
+        # Add exception info if present
+        if record.exc_info:
+            log_data["exception"] = self.formatException(record.exc_info)
+
+        # Add extra fields
+        if hasattr(record, "extra"):
+            log_data.update(record.extra)
+
+        return json.dumps(log_data)
+
+
+def setup_logging(
+    level: int = logging.INFO,
+    format_type: str = "json",
+    output_file: Optional[str] = None
+) -> logging.Logger:
+    """Setup logging configuration.
+
+    Args:
+        level: Logging level (DEBUG, INFO, WARNING, ERROR, CRITICAL)
+        format_type: "json" or "text"
+        output_file: Optional file path for log output
+
+    Returns:
+        Configured logger
+    """
+    logger = logging.getLogger("wikijs")
+    logger.setLevel(level)
+
+    # Remove existing handlers
+    logger.handlers.clear()
+
+    # Create handler
+    if output_file:
+        handler = logging.FileHandler(output_file)
+    else:
+        handler = logging.StreamHandler(sys.stdout)
+
+    # Set formatter
+    if format_type == "json":
+        formatter = JSONFormatter()
+    else:
+        formatter = logging.Formatter(
+            "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
+        )
+
+    handler.setFormatter(formatter)
+    logger.addHandler(handler)
+
+    return logger
+
+
+# Create default logger
+logger = setup_logging()