fix(schema): re-sync trace-v0.2.json with trace-spec

[rajnisht7]

The published schema at agentrust-io.com/schema/trace-v0.2.json had drifted from the normative source in trace-spec again (same issue as #40).

Two things are out of sync:

• subject.pattern was an unanchored prefix check (^(spiffe://|did:)), so it accepted things like spiffe://example.org or did:x even though neither is a real, complete identity. Upstream fixed this in trace-spec#248.
• platform's description had fallen behind trace-spec#234/#272 and no longer mentioned that origin.kind other than self requires platform: software-only.

Re-synced both from trace-spec's schema/trace-claim.json. Verified byte-for-byte identical to upstream after the change, and confirmed the $id still matches. Nothing else in the repo references these fields, so this only touches the one file.

[lywinged]

Checked on 80459f5 against trace-spec fc38496. Before this change the served file differs from schema/trace-claim.json in exactly the three places the body names, subject.pattern and the two descriptions; after it the two files are byte-identical, jq -S agrees, and $id is unchanged. The two revocation schemas served beside it match their sources too. The three upstream commits behind the drift are agentrust-io/trace-spec#248 on 2026-08-31, #272 on 09-02 and #234 on 09-03.

One reference to fix: #40 in this repository is the em-dash change of 2026-08-27. The previous resync is 7f5ed33 of 2026-08-19, which also added schema-parity.yml, and it carries no PR number.

What the interval shows: that workflow compares the served file with trace-spec main daily at 06:17Z, so it has had a difference to report at every run since 09-01, and the fix arrived four days later by hand. The guard reports and nothing resyncs. A push to schema/ in trace-spec opening the sync PR here, or this workflow opening one when its scheduled run fails, would close that loop; a suggestion for the maintainers, not a condition on this PR.

Tool-assisted: the checks and this write-up.

[imran-siddique]

Reviewed the schema sync against the normative trace-spec source. After the newly released parity job exposed a newer upstream change, I copied the exact normative schema at 8aebaa00dfadd5bbb0daf777951984e4fdb25f2a, including the confirmation-key private-member rejection rules. This keeps the published schema aligned with the normative source.