feat(macro): Macro Vibes — 8-indicator daily snapshot + composite score

New backend pipeline: 8 free public macro signals fetched in parallel,
upserted once per calendar day, served via /api/macro/{snapshot,history}.

  - AHR999 (computed from Binance 200d klines)
  - Altcoin Season Index (CoinGecko top-50 30d)
  - Fear & Greed (alternative.me)
  - BTC dominance, ETH/BTC ratio
  - Stablecoin supply (DeFiLlama)
  - Spot BTC ETF net flow (Farside)
  - BTC perp open interest (Binance fapi)

Each fetcher is independently @_none_on_fail decorated so one outage
can't take down the snapshot; scoring renormalises across whichever
indicators returned a value. Daily cron at 03:00 UTC; on startup a
fire-and-forget bootstrap fills today's row if missing.

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

app/models.py

@@ -1,9 +1,10 @@
-from datetime import datetime, timezone
+from datetime import date, datetime, timezone
 from typing import List, Optional
 
 from sqlalchemy import (
     BigInteger,
     Boolean,
+    Date,
     DateTime,
     Float,
     ForeignKey,
@@ -412,3 +413,34 @@ class TelegramBinding(Base):
     last_alert_at:        Mapped[Optional[datetime]] = mapped_column(DateTime, nullable=True)
     total_alerts_sent:    Mapped[int] = mapped_column(Integer, nullable=False, default=0)
     total_alerts_failed:  Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+
+
+class MacroSnapshot(Base):
+    """Daily snapshot of all macro indicators surfaced on the BTC page.
+
+    One row per calendar date. Every indicator column is nullable — any single
+    upstream API failing must not block the rest from being recorded.
+    Composite score is computed at insert time by app/services/macro/scoring.py
+    against whichever indicators successfully fetched (the formula degrades
+    gracefully if a few are missing).
+    """
+    __tablename__ = "macro_snapshots"
+
+    id:            Mapped[int]      = mapped_column(Integer, primary_key=True)
+    snapshot_date: Mapped[date]     = mapped_column(Date, nullable=False, unique=True, index=True)
+    captured_at:   Mapped[datetime] = mapped_column(DateTime, nullable=False, default=utcnow)
+
+    ahr999:                Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    altcoin_season_index:  Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    fear_greed:            Mapped[Optional[int]]   = mapped_column(Integer, nullable=True)
+    fear_greed_label:      Mapped[Optional[str]]   = mapped_column(String(32), nullable=True)
+    btc_dominance_pct:     Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    eth_btc_ratio:         Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    stablecoin_supply_usd: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    etf_flow_net_usd_1d:   Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    btc_open_interest_usd: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+
+    composite_score: Mapped[Optional[float]] = mapped_column(Float, nullable=True)
+    regime_label:    Mapped[Optional[str]]   = mapped_column(String(16), nullable=True)
+
+    raw_json: Mapped[Optional[str]] = mapped_column(Text, nullable=True)