feat: rebuild games as a native arcade

[keys-i]

What changed

• replace the external game catalog/launcher with eleven original clean-room Rust game modes
• add one event-driven Crossterm UI with safe terminal restoration, resize fallback, deterministic randomized setup, and no network or child processes
• preserve the prepared native fetch command and package both binaries in one maturin wheel
• include locked third-party license notices and assert them during clean-wheel smoke tests

Part of #1

Verification

• cargo test --locked — 13 unit and 3 CLI tests pass
• cargo fmt --all --check
• cargo clippy --all-targets --locked -- -D warnings
• locked release build and clean maturin wheel smoke test
• ShellCheck 0.11, Actionlint 1.7.12, and Zizmor 1.29 pedantic
• independent fallback gatekeeper: VERDICT: PASS

Measurements

Apple M3 Pro, Darwin 25.5.0 ARM64, Rust 1.97.1, Hyperfine 1.20.0; 100 runs after 20 warmups:

Command	Mean ± σ	Binary
fetch --plain	1.4 ± 0.1 ms	336,224 B
games list --plain	1.5 ± 0.1 ms	438,992 B

The macOS ARM64 wheel is 410,899 B including both binaries, metadata, project/dependency licenses, and CycloneDX SBOM. The former launcher list is not an equivalent workload, so no comparative speed claim is made.

Risk and rollback

• interactive rendering is cross-platform through Crossterm; CI builds and smoke-tests Linux, macOS, and Windows
• revert c0942ff to restore the previous external launcher

Review

• Public behavior, help, and relevant docs are updated.
• New or changed failure paths have observable tests.
• No research clones, copied upstream source/assets, secrets, or generated benchmark output are included.
• I will follow the Code of Conduct.