wip: implement structured logging system with performance optimizations

[bitkojine]

• Add ExtensionLogger with configurable log levels and VSCode OutputChannel integration
• Implement WebviewLogger with message batching (10 msgs/1s) to reduce postMessage overhead
• Create PerformanceLogger for threshold-based performance tracking (100ms default)
• Add ExtensionWebviewLogger for handling webview log batches
• Replace console.log spam with structured logging throughout codebase
• Implement child logger contexts for better traceability
• Add comprehensive logging redesign specification with implementation phases
• Optimize webview-to-extension communication with batched log forwarding
• Add environment-aware logging capabilities for dev/prod separation

Performance improvements:

• Reduce postMessage calls by ~90% through batching
• Eliminate verbose PerfTracker event logging
• Only log performance operations exceeding thresholds
• Remove console method wrapping overhead in bootstrap

Note: Work in progress - logging system foundation complete, migration of existing console calls ongoing