feat: add seasonal Workshop client evidence workflow

[Teakowa]

Summary

Implements the repository-owned/offline portion of #21 as a Draft PR stacked on #19.

• Adds workshop_rs::live_capture::LiveCapture for provenance-rich manually recorded client captures: client/season/time/environment, locale, catalog identity, authoritative workshop_rs::census::CensusIdentity digest/shards, raw artifact pinning, and Define the Workshop conformance result contract and stable feature identities #18 feature-attributed results.
• Adds offline LiveCapture::diff and workshop-rs-cli seasonal-diff <previous.json> <current.json> [--json] with locale, catalog, content, semantic/schema, and separate runtime-uncertainty classifications.
• Validates live-client evidence linkage, raw artifact revision/path/SHA-256, matching catalog/locale/client provenance, and current-catalog validation when requested. Historical captures remain comparable for catalog drift.
• Documents the manual en-US baseline and zh-CN sweep, import/export procedure, raw artifact retention, and reviewed follow-up path in ADR-0005.

Explicit client boundary

No Overwatch client was available for this implementation. No real client capture or fabricated live evidence is committed. The schema/diff tests use clearly labelled synthetic unit inputs only. Manual client import/export and gameplay validation remain maintainer-only acceptance boundaries; import/export does not claim runtime correctness.

Checks

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

Refs #21 (manual client validation remains open).

[Teakowa]

Independent QA follow-up addressed in commit 72ff506:

• Added a legal synthetic schema-only capture helper to exercise seasonal-diff text and --json success paths; no client artifact or live evidence is committed.
• Enforced normalized catalog target game ↔ capture game linkage.
• Enforced result-level client environment ↔ capture environment linkage.
• Added negative coverage for both provenance mismatches.

Please perform a fresh QA pass against the new head. The real Overwatch client boundary remains explicitly manual/unverified.

[Teakowa]

Fresh independent QA: PASS — VERIFIED on head 72ff506.

• Synthetic capture drives CLI text and --json success paths without any real client artifact.
• Catalog target game and result environment linkage are enforced and negatively tested.
• Schema/raw SHA-256/locale/catalog/census provenance, feature attribution, drift classes, and runtime uncertainty all pass.
• Full local gates: 160 tests passed; stable/Rust 1.85 CI and catalog check passed.

Remaining explicit boundary: no real Overwatch import/export or gameplay evidence; maintainer-only manual validation remains open per ADR-0005.

[Teakowa]

Fresh independent QA — VERIFIED / PASS

Exact head reviewed: a7215dcb56d1535e1236a416bdbd530de4126bb8.

• CensusIdentity has one canonical definition in workshop_rs::census; live_capture only consumes/re-exports it.
• Offline validation rejects malformed identities, missing client/artifact provenance, mismatched catalog/locale/artifact data, and invalid result evidence.
• Synthetic inputs are explicitly labelled; no real client capture or fabricated runtime evidence is committed.
• Local fmt, Clippy, workspace/all-targets tests, catalog check, and diff check passed.
• Stable and Rust 1.85 CI passed on this exact head; worktree is clean.
• PR history/body use only Refs #21; no closing reference is present, and Issue Establish the seasonal live-client Workshop validation and structured-diff workflow #21 remains OPEN.

The previous QA on 72ff506 is superseded by this exact-head review. The repository-owned offline workflow is verified; real en-US/zh-CN client capture and runtime acceptance remain maintainer-only work under #21.