chore: release v0.6.3 (#3)

chore: sync all version references to 0.6.2

- tui/Cargo.toml: 0.6.0 → 0.6.2
- tui/Cargo.lock: 0.6.0 → 0.6.2
- src/mcp/client.ts: MCP client version 0.6.0 → 0.6.2