Support installation via GitHub Releases

[anujmindfire]

Allow users to install DeepScanBot directly by downloading prebuilt binaries from GitHub Releases.

Requirements :-

Publish binaries for : Linux amd64, Linux arm64, macOS Intel, macOS Apple Silicon, Windows amd64
Include SHA256 checksums
Include release notes
Archive binaries (.tar.gz / .zip)
Ensure binaries are executable after extraction
Update installation documentation
Add upgrade instructions
Add uninstall instructions

Acceptance Criteria :-
Users can download a binary from GitHub Releases.
Binary runs without additional dependencies.
Checksums are published.
Documentation is complete.