datasets: seed the first two agent-trace entries

[gautamgb]

Summary

The follow-up promised in #62: the two seed entries and index.csv, now that the schema and validator have merged.

• DSGAI-TRACE-mcp-declared-effect-flip-stale-autoapproval - a tool re-declares destructiveHint: true after an approval policy has already cached it into an auto-approve class, and the next call runs destructively with no human asked.
• DSGAI-TRACE-mcp-output-schema-expansion-context-overshare - a tool's output schema widens under a stable server identity, and a schema-agnostic context append carries three unentitled fields into the model context, the user-facing answer, and the observability sink.

Both are derived_from_public_documentation: fully synthetic sessions built around a precondition the MCP specification itself establishes (annotations untrusted from an untrusted server, no version field on a tool definition, tools/list_changed as a SHOULD, outputSchema obligations attaching to whatever schema is current), plus CVE-2025-54136 for the first entry, with the entry stating plainly what the CVE does and does not establish about the non-adversarial mechanism it illustrates.

index.csv is rebuilt against main as it stands now, so it includes #67's entry alongside these two - three rows total.

Verification

$ python validate.py
OK: 3 entries + example.json validated against schema.

$ python build_index.py
Wrote index.csv with 3 entries.

Rebased on the current main tip in a clean worktree (not cherry-picked over a stale base), so there's nothing here that predates #67's entry or the merged schema.

[emmanuelgjr]

Thanks @gautamgb, reviewed and verified locally on current main together with #73/#74: validate.py passes (3 entries), the rebuilt index.csv matches yours, and the evidence is scoped honestly. The CVE-2025-54136 note on what it does and doesn't establish is exactly the right register.

One change before merge, a repository-wide attribution policy rather than anything about these entries: please remove affiliation from the contributor object in both entries. Attribution in this repo is a person's name plus, optionally, one ORCID iD. orcid stays; it's a persistent, neutral identifier that helps citation. affiliation is free text, and it's the field through which organizational credit would enter the dataset over time, so we're closing it at the schema level in #75 (after which it fails validation).

So each entry becomes:

"contributor": {
  "name": "Bharti, Gautam",
  "orcid": "0009-0001-4448-1438"
}

Once that's pushed I'll approve and merge.

[emmanuelgjr]

Affiliation dropped, ORCID kept — thanks for the quick turnaround. Re-verified on the rebased head: 3 entries validate, index.csv rebuilds identically, 18 tests pass. Merging.