Fix: Handle empty database path when current directory is invalid

[echobt]

Summary

Fixes a bug where the server API crashes or behaves unexpectedly when the current directory cannot be determined, leading to an empty database path.

Problem

When std::env::current_dir() fails, config.db_path() returns an error. The current implementation in �pi.rs uses .unwrap_or_default() which results in an empty path string. This is passed to Database::new(), potentially causing initialization failures or creating/accessing a database at an invalid location.

Solution

Explicitly handle the Result from config.db_path() in status and search endpoints. If the path cannot be determined, return a 500 Internal Server Error with a descriptive message instead of silently falling back to a default empty path.

Testing

• Verified code compilation (fix is logic-based standard error handling).
• The change ensures that failure to determine context results in a clear error rather than undefined behavior.

Related Issue

Fixes PlatformNetwork/bounty-challenge#44