ticker-validate: add /api/ticker/validate endpoint

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/routers/ticker_validate.py

@@ -0,0 +1,78 @@
+"""Per-ticker validation + historical-price endpoints.
+
+These power the dashboard's "Add a position" form. Neither endpoint
+persists holdings — they wrap the existing Yahoo chart fetcher and
+optionally seed anonymous ticker_universe (validate only).
+
+Both endpoints are gated behind ``require_paid`` so they match the rest
+of the import surface.
+"""
+from __future__ import annotations
+
+from datetime import datetime, timezone
+
+import httpx
+from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.auth import require_auth
+from app.db import get_session, utcnow
+from app.logging import get_logger
+from app.models import Quote as QuoteModel
+from app.services.access import require_paid
+from app.services.market import (
+    UA, YAHOO_CHART, Quote, _yahoo_range_covering, fetch_yahoo,
+)
+from app.services.ticker_universe import upsert_tickers
+
+
+log = get_logger("ticker_validate")
+
+router = APIRouter(dependencies=[Depends(require_auth)])
+
+
+@router.get(
+    "/ticker/validate",
+    dependencies=[Depends(require_paid)],
+)
+async def validate_ticker(
+    symbol: str,
+    session: AsyncSession = Depends(get_session),
+) -> dict:
+    """Live quote for one ticker.
+
+    Returns ``{ok: true, symbol, price, currency, as_of}`` on success
+    or ``{ok: false, error}`` when the symbol isn't recognised. Seeds
+    ticker_universe + writes a Quote row as a side-effect on success
+    so the dashboard's /api/universe call picks it up on the next
+    refresh."""
+    symbol = symbol.strip().upper()[:32]
+    if not symbol:
+        return {"ok": False, "error": "symbol required"}
+
+    async with httpx.AsyncClient(follow_redirects=True, timeout=15) as client:
+        quote = await fetch_yahoo(client, symbol, symbol, "")
+
+    if quote.error or quote.price is None:
+        log.info("ticker.validate.miss", symbol=symbol,
+                 error=(quote.error or "no price")[:120])
+        return {"ok": False, "error": "Symbol not recognised"}
+
+    # Side-effect: seed the universe + write the quote so /api/universe
+    # has data on the next minute-cycle refresh.
+    await upsert_tickers(session, [symbol])
+    session.add(QuoteModel(
+        symbol=quote.symbol, source=quote.source, label=quote.label,
+        group_name="universe", price=quote.price, currency=quote.currency,
+        as_of=quote.as_of, changes=quote.changes or None, error=None,
+        fetched_at=utcnow(),
+    ))
+    await session.commit()
+
+    return {
+        "ok": True,
+        "symbol": quote.symbol,
+        "price": quote.price,
+        "currency": quote.currency,
+        "as_of": quote.as_of,
+    }