Enhance logging for VS Code and OpenCode paths, improving visibility

[rajbos]

This pull request improves the logging and diagnostics in the CopilotTokenTracker class to provide clearer insights into which VS Code and OpenCode session paths are being checked and found. The main focus is on making the scanning process more transparent for debugging and troubleshooting.

Enhanced logging for session path discovery:

• Now logs all candidate VS Code user paths before checking which ones exist, including a list of each candidate path.
• After scanning, logs which VS Code paths were actually found on disk, including a detailed list of the found paths.

Improved diagnostics for Copilot CLI and OpenCode session checks:

• Adds a log statement indicating which Copilot CLI session-state directory is being checked and whether it exists.
• Adds log statements for both the OpenCode JSON session directory and the SQLite database path, including their existence status.
• Refactors OpenCode database path handling to ensure consistent logging and path usage.…of candidate paths and existence checks