feat(fundamentals): A4 — additive API v1 (earnings, metrics, valuation, reads)

GET /fundamentals/{symbol} now returns the additive v1 objects alongside the
unchanged legacy fields (no legacy growth mapped onto the SEC TTM metric).

- earnings: next (date/session/days_until) + recent (<=4, with surprise_pct)
  from earnings_events.
- metrics: fixed key set (value + dated history + per-metric SIC-peer industry
  object + source=sec); net_debt has no industry (size-dependent).
- valuation: P/E, FCF yield, market_cap_est computed at REQUEST TIME from the
  derived TTM inputs x the latest ohlcv close (no stored valuation); guarded to
  null on missing/invalid inputs; pe_industry / fcf_yield_industry peer stats.
- reads: deterministic outputs in a SEPARATE object (header + per-metric reads).

Peer queries are batched and CIK-deduplicated by 2-digit SIC; industry omitted
below 5 valid peers. Schema extended with optional typed sub-models; the router
merges legacy + v1 so every existing field is preserved.

Tests: 4 (full assembly incl. peer industry + valuation + additive-merge, no-cik
null metrics, <5-peers omitted, price-guarded valuation).

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

app/routers/fundamentals.py

@@ -9,6 +9,7 @@ from app.dependencies import get_db, require_access
 from app.schemas.common import APIEnvelope
 from app.schemas.fundamental import FundamentalResponse
 from app.services.fundamental_service import get_fundamental
+from app.services.fundamentals_api_service import build_fundamentals_v1
 
 router = APIRouter(tags=["fundamentals"])
 
@@ -30,14 +31,13 @@ async def read_fundamentals(
     _user=Depends(require_access),
     db: AsyncSession = Depends(get_db),
 ) -> APIEnvelope:
-    """Get latest fundamental data for a symbol."""
+    """Get latest fundamental data for a symbol (legacy fields + additive v1)."""
     record = await get_fundamental(db, symbol)
+    v1 = await build_fundamentals_v1(db, symbol)
 
-    if record is None:
-        data = FundamentalResponse(symbol=symbol.strip().upper())
-    else:
-        data = FundamentalResponse(
-            symbol=symbol.strip().upper(),
+    legacy: dict = {}
+    if record is not None:
+        legacy = dict(
             pe_ratio=record.pe_ratio,
             revenue_growth=record.revenue_growth,
             earnings_surprise=record.earnings_surprise,
@@ -47,4 +47,5 @@ async def read_fundamentals(
             unavailable_fields=_parse_unavailable_fields(record.unavailable_fields_json),
         )
 
+    data = FundamentalResponse(symbol=symbol.strip().upper(), **legacy, **v1)
     return APIEnvelope(status="success", data=data.model_dump())