feat: add polygon.aggregates eval case to seed.jsonl

[SebAustin]

---

title: "feat: add polygon.aggregates eval case to seed.jsonl"
labels: [feat, eval, w2]
assignees: [SebAustin]

Problem

polygon.aggregates is registered on the MCP server but absent from
evals/cases/seed.jsonl. Nightly --full never exercises the Polygon client,
so regressions there would not move eval metrics.

Acceptance criteria

• New case polygon-aapl-daily-2025 in evals/cases/seed.jsonl with
  offline fixture and live expected values.
• evals/dispatch.py route already exists; extend judge compaction if
  bar payloads are large.
• Offline and live --full runs pass with n_pass == n_cases.
• README eval table updated with the new case count.

References

• src/mcp_financial_data/tools/polygon.py
• ADR 0009 — eval harness online dispatch