feat: migrate modules into independent crates

[brasga-a]

Summary

• add the seven statically linked Luna module crates
• add the Notch module contract, route model, registry and shared primitives
• move launcher, clock and resources rendering behind the host contract
• register concrete modules from shell-app
• preserve the current configuration and module documentation changes

Validation

• cargo check --workspace --all-targets
• cargo clippy --workspace --all-targets -- -D warnings
• non-GPUI workspace tests pass

Full workspace tests are currently blocked at native linking when libxkbcommon-x11-dev is absent on the host.