feat(workshop): model contextual literal semantics

[e54-bot]

Summary

• model contextual literal substitutions as per-parameter catalog metadata
• normalize accepted source literals into canonical WIR and validate only declared aliases
• cover Boolean/Number, Null/vector, empty string contexts while preserving comparison polymorphism and the Wait Until numeric exception
• add executable conformance witnesses and provenance/docs for the reviewed OverPy contract

Validation

• cargo test --workspace --all-targets --quiet
• cargo fmt --all --check
• cargo clippy --workspace --all-targets -- -D warnings
• cargo run --locked -p workshop-rs --bin workshop-catalog-gen -- check
• git diff --check

Fixes #135

[Teakowa]

Major — crates/workshop-rs/src/catalog/data/catalog.json (version)

This PR changes canonical catalog semantics and the digest, but leaves the dataset version at 0.1.2. ADR-0001 Decision 5 requires catalog-version to be bumped by any dataset change; otherwise the same catalog version identifies two different semantic datasets. Bump the catalog version and regenerate/update the digest pin.

Minor — crates/workshop-rs/src/catalog/data/catalog.json provenance / docs/provenance.md

The new contextual-semantics evidence points at mutable OverPy master URLs. The existing reference-pinning contract requires version/content-pinned evidence so the audited claim remains attributable later. Point these references at the exact reviewed OverPy pin/commit (or otherwise record the exact audited identity) instead of master.

[Teakowa]

LGTM