feat(command): add bounded command schema foundation

[zackees]

Summary

Adds the first bounded, facade-owned command-schema layer for #215. clap remains a private, opt-in implementation detail; default consumers do not resolve it.

This is intentionally a foundation rather than fastled-wasm adoption: optional values, repetition, conflicts, requirements, and help modelling still need the fuller schema requested by the issue.

Validation

• soldr --no-cache cargo test --features command-schema --test command_schema_contract
• soldr --no-cache cargo test --no-default-features
• soldr --no-cache cargo clippy --features command-schema --all-targets -- -D warnings
• review follow-up clean after fixes for selected-path collection, schema panic prevention, test feature gating, and native non-UTF-8 input.

Stack

• Base: feat/json-documents / feat(json): bounded owned JSON documents #212.
• Coordinates with Rebase FastLED infrastructure onto kernal-api FastLED/cli#242, which must keep its existing command parser until this schema is complete.

[zackees]

Added the error-context migration support in b73b195, 9f978f2, and 073995a: bounded message construction, alternate source-chain rendering, Option/Result context, and generic ? conversions through the boxed facade boundary. Verified with soldr cargo test --features error-context error::tests::context_retains_source_and_bounds_display. fastled-wasm now consumes this facade without a direct anyhow dependency.

[zackees]

Added b2d3ec7 for the requested automatic GitHub release flow with registry publishing deferred behind explicit repository variables. Focused release-workflow tests and YAML parsing pass.