fix(conformance): replace P0 test API terminology

[Teakowa]

Summary

• Rename the public real-project expectation surface from p0 to real_projects and RealProject* / REAL_PROJECT_* names.
• Rename the real-project evidence manifest and remove phase-specific P0 terminology from tests, docs, provenance, and catalog metadata.
• Preserve all case identities, source hashes, residuals, and admitted gaps.
• Leave Wright consumer migration for the released API follow-up described by Replace phase-specific P0 test API terminology with durable conformance naming #96.

Verification

• cargo fmt --all --check
• cargo clippy --workspace --all-targets --locked -- -D warnings
• cargo test --workspace --all-targets --locked
• cargo run --locked -p workshop-rs --bin workshop-catalog-gen -- check
• cargo metadata --locked --no-deps
• Independent baseline/treatment contract comparison: VERIFIED

Fixes #96