feat: Improves bridge termination and enhance release process with changelog

[Yashh56]

This pull request improves the update and installation process for RelWave by ensuring that all relevant processes are properly terminated before updates, preventing file access errors, and enhancing the user experience with release notes. It also updates documentation and refines how release notes are displayed in the app.

Installer and Update Reliability:

• The NSIS installer pre-install hook (src-tauri/nsis/installer-hooks.nsi) now kills not only bridge.exe but also node.exe and the main app process, and increases the wait time to ensure all file handles are released before updating resources like better_sqlite3.node.
• A new Tauri command bridge_kill is added (src-tauri/src/bridge/commands.rs, src-tauri/src/bridge/mod.rs, src-tauri/src/main.rs) to explicitly terminate the bridge process and wait for it to fully exit, ensuring that updates do not fail due to locked files. [1] [2] [3] [4]
• The updater hook (src/features/settings/hooks/useUpdater.ts) now calls bridge_kill before applying updates, improving reliability on Windows by preventing "Error opening file for writing" issues. [1] [2]

Release Notes and User Experience:

• The GitHub release workflow (.github/workflows/release.yml) is updated to auto-generate release notes from merged PRs and commits, which are then shown in the app's "What's New" dialog.
• The release notes parser (src/components/shared/WhatsNewDialog.tsx) now detects and ignores placeholder or content-free release notes, falling back to generic highlights for a better user experience.

Documentation:

• The README.md is updated to reflect the new version (0.6.0-beta.5) and corrects the Quick Start link.