fix(fundamentals): compute eps_growth_yoy read; cover same-day + price guards

- The eps_growth_yoy read was never computed, leaving that fixed by_key entry
  null even with sufficient EPS history; now growth_read() is applied to EPS
  history just like revenue.
- Tests: same-day earnings returns as next with days_until 0 (and not in
  recent); zero close guards valuation to null; eps read populated. Fixture
  seeds three fiscal years so YoY growth reads have a >=3 run. 9 API tests pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/services/fundamentals_api_service.py

@@ -198,6 +198,7 @@ def _build_reads(metrics: list[dict], valuation: dict | None) -> dict[str, Any]:
         return [_Pt(p["value"]) for p in by_metric.get(key, {}).get("history", [])]
 
     growth = reads.growth_read(hist("revenue_growth_yoy"))
+    eps_growth = reads.growth_read(hist("eps_growth_yoy"))
     op_margin = reads.margin_read(hist("operating_margin"))
     fcf_margin = reads.margin_read(hist("fcf_margin"))
     share = reads.share_count_read(by_metric.get("share_count_change_yoy", {}).get("value"))
@@ -209,6 +210,7 @@ def _build_reads(metrics: list[dict], valuation: dict | None) -> dict[str, Any]:
     by_key: dict[str, str | None] = {k: None for k in _READ_KEYS}
     by_key.update({
         "revenue_growth_yoy": growth,
+        "eps_growth_yoy": eps_growth,
         "operating_margin": op_margin,
         "fcf_margin": fcf_margin,
         "share_count_change_yoy": share,