Set Cargo.toml license field and reconcile registry metadata (Apache-2.0 already at repo root)

[adiled]

The repo's LICENSE file is Apache-2.0 and has been since the project shipped. The original ask was a dual-license recommendation; that recommendation is walked back. The maintainer's actual choice is Apache-2.0 (matching the orchd repo) and the dossier confirms it.

The remaining gaps are registry-side and crate-name-side, not file-side.

Action

• Set the license field in orch/Cargo.toml to "Apache-2.0". Currently unset.
• Update README to declare the license as Apache-2.0 explicitly (the SPEC.md mentions it; the README should too).
• Rename the crate. orch is already taken on crates.io by guywaldman/orch (an LLM orchestration library, ~15k downloads). cargo install orch is impossible. Recommended replacement: orchfile (available on crates.io, doubles as the file format name, lets the binary inside stay named orch). The repo name and the binary name can stay as is; only the crate's name in Cargo.toml changes.
• After the rename and license-field set, run cargo publish --dry-run to verify all metadata.
• Update orchd's Cargo.toml to depend on the renamed crate (currently a git dep on adiled/orch).

Context
Tracked in the distribution playbook at adiled/distribution. orch and orchd are a coherent pair under one license, not the dual-license mix the prior dossier inferred.

~ distribution team