Add CLI Startup Profiling Feature

This PR adds a profiling feature to the CLI to help diagnose the slow startup times on Windows compared to MacOS (Issue #100).

Changes

1. Added a --profile flag to enable performance profiling
2. Created a performance tracking module that:
   • Measures timing of key initialization steps
   • Reports detailed timing information
   • Provides platform-specific diagnostics on Windows
3. Added a test-profile command to easily test the profiling feature
4. Optimized Sentry initialization to only run when needed

How to Use

Run any command with the --profile flag to see timing information:

# Basic usage
mycoder --profile --help

# With a specific command
mycoder --profile test-profile

The profiling output shows:

• Timing for each initialization step
• Total startup time
• On Windows: additional platform diagnostics to help identify bottlenecks

Example Output

📊 Performance Profile:
=======================
Module initialization: 10.12ms (10.12ms)
After imports: 150.34ms (140.22ms)
Main function start: 269.99ms (119.65ms)
After dotenv config: 270.10ms (0.11ms)
After Sentry init: 297.57ms (27.48ms)
Before package.json load: 297.57ms (0.00ms)
After package.json load: 297.78ms (0.21ms)
Before yargs setup: 297.78ms (0.00ms)
After yargs setup: 401.45ms (103.67ms)
Total startup time: 401.45ms
=======================

Next Steps

Based on the profiling data, we can identify and optimize the slowest parts of the initialization process, particularly focusing on Windows-specific optimizations.

Closes #100