Fix Antigravity local LSP detection

[Finesssee]

Summary

• Detect the current language_server.exe process alongside the legacy language_server_windows* process.
• Keep required CSRF-token and extension-port parsing intact; the existing API-port discovery is unchanged.

Fixes #161

Report

#161

Commit

7a0e709887a6d6c6b275f194b48ac717c386b582

Changed files

• rust/src/providers/antigravity/mod.rs

TDD proof

• RED: cargo test --manifest-path rust/Cargo.toml parses_current_language_server_process failed before the process-name fix because the parser rejected language_server.exe.
• GREEN: the same focused test passed after the fix.

Validation

• cargo test --manifest-path rust/Cargo.toml
• cargo test --manifest-path apps/desktop-tauri/src-tauri/Cargo.toml
• cargo fmt --all -- --check
• cargo clippy --manifest-path rust/Cargo.toml --all-targets -- -D warnings
• cargo clippy --manifest-path apps/desktop-tauri/src-tauri/Cargo.toml --all-targets -- -D warnings
• pnpm.cmd run build (includes check-locale)
• pnpm.cmd run test

Native validation

The native Antigravity language server is not installed on this Windows machine, so a live CIM query against it was not possible. The safe process-name-only probe confirmed that condition; no command lines or tokens were logged.