Bitcoind process management DRAFT_PR

[R27-pixel]

Summary

This PR adds initial process management support for Bitcoin Core (bitcoind) in PDM.

Changes

• Added controls to start and stop the bitcoind process.
• Added process state tracking and UI updates.
• Improved error handling for process startup and shutdown.
• Introduced a reusable foundation for future process management (e.g., P2Pool).

This PR only covers Bitcoin Core process management. P2Pool process management will be added in a separate PR.

[codecov]

Codecov Report

❌ Patch coverage is 78.38196% with 652 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/app.rs	42.54%	235 Missing ⚠️
src/components/bitcoin_status_view.rs	57.85%	169 Missing ⚠️
src/main.rs	50.58%	85 Missing ⚠️
src/process_manager.rs	70.16%	71 Missing ⚠️
src/bitcoin_logs.rs	83.81%	39 Missing ⚠️
src/components/bitcoin_client.rs	96.03%	20 Missing ⚠️
src/components/p2pool_websocket.rs	95.97%	14 Missing ⚠️
src/components/p2pool_client.rs	95.42%	8 Missing ⚠️
src/config.rs	61.90%	8 Missing ⚠️
src/components/status_bar.rs	91.89%	3 Missing ⚠️

📢 Thoughts on this report? Let us know!