ingest: switch wealthfolio to pg-sync mirror reads

The previous SQLite-direct reader queried `holdings_snapshot` (singular)
and `accounts.type` — both wrong against the live wealthfolio schema
(plural `holdings_snapshots`, column `account_type`). It silently
returned [] via the OperationalError fallback, leaving fire-planner with
stale account snapshots.

Switch to reading from the wealthfolio_sync PG mirror. The pg-sync
sidecar (defined in infra/stacks/wealthfolio) hourly mirrors SQLite to
Postgres with a clean schema. We read from `daily_account_valuation`
which already has total_value, cost_basis, and explicit fx_rate_to_base
per row — no JSON-decoding of position blobs.

CLI ingest no longer takes --db-path (no kubectl-exec gymnastics);
reads WEALTHFOLIO_SYNC_DB_CONNECTION_STRING from env. Falls back to
DB_CONNECTION_STRING for single-DB local dev.

13 new tests covering: latest-per-account, multi-currency FX, explicit
as-of, empty mirror, null cost_basis, full pipeline through upsert.
140 tests pass; mypy strict + ruff clean.

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

fire_planner/ingest/wealthfolio_pg.py

@@ -0,0 +1,115 @@
+"""Wealthfolio ingest from the wealthfolio_sync Postgres mirror.
+
+The wealthfolio pod runs a `pg-sync` sidecar that hourly snapshots its
+local SQLite to the `wealthfolio_sync` PG database. Reading from that
+mirror (rather than the live SQLite via kubectl-exec) is more reliable:
+no cross-pod copy, no schema-mismatch swallowing, multi-process safe,
+and Grafana already trusts it.
+
+Source schema (defined in `infra/stacks/wealthfolio/main.tf`):
+
+    accounts(id, name, account_type, currency, is_active)
+    daily_account_valuation(id, account_id, valuation_date,
+                            account_currency, base_currency,
+                            fx_rate_to_base,
+                            cash_balance, investment_market_value,
+                            total_value, cost_basis, net_contribution)
+
+`daily_account_valuation` is the right table for time-series NW per
+account — `total_value` is in `account_currency`; multiply by
+`fx_rate_to_base` to get the user's base (typically GBP). The mirror
+filters out the synthetic `'TOTAL'` account_id so we never see it here.
+"""
+from __future__ import annotations
+
+import os
+from datetime import date
+from decimal import ROUND_HALF_EVEN, Decimal
+from typing import Any
+
+from sqlalchemy import text
+from sqlalchemy.ext.asyncio import AsyncEngine, AsyncSession, create_async_engine
+
+_TWO_PLACES = Decimal("0.01")
+
+
+def create_wf_sync_engine_from_env() -> AsyncEngine:
+    """Engine for the wealthfolio_sync mirror DB.
+
+    Reads `WEALTHFOLIO_SYNC_DB_CONNECTION_STRING`; falls back to
+    `DB_CONNECTION_STRING` for single-DB local dev. Raises if neither
+    is set so callers fail loudly instead of silently using the wrong DB.
+    """
+    url = (
+        os.environ.get("WEALTHFOLIO_SYNC_DB_CONNECTION_STRING")
+        or os.environ.get("DB_CONNECTION_STRING")
+    )
+    if not url:
+        raise RuntimeError(
+            "WEALTHFOLIO_SYNC_DB_CONNECTION_STRING (or DB_CONNECTION_STRING) "
+            "must be set to read the wealthfolio_sync mirror"
+        )
+    return create_async_engine(url, pool_pre_ping=True)
+
+
+async def read_account_snapshots_from_pg(
+    wf_session: AsyncSession,
+    as_of: date | None = None,
+) -> list[dict[str, Any]]:
+    """Read latest NW per account from `daily_account_valuation`.
+
+    Returns a list of dicts with the same shape as
+    `wealthfolio.read_account_snapshots()`, so `upsert_snapshots()`
+    accepts either source.
+
+    If `as_of` is None, picks the max `valuation_date` in the mirror
+    (i.e. "latest"). If `as_of` is given, returns rows for that exact
+    date; if no rows exist, returns [].
+    """
+    if as_of is None:
+        latest = (await wf_session.execute(
+            text("SELECT MAX(valuation_date) FROM daily_account_valuation"))).scalar()
+        if latest is None:
+            return []
+        target = latest if isinstance(latest, date) else date.fromisoformat(str(latest))
+    else:
+        target = as_of
+
+    rows = (await wf_session.execute(
+        text("""
+            SELECT a.id            AS account_id,
+                   a.name          AS account_name,
+                   a.account_type  AS account_type,
+                   COALESCE(d.account_currency, a.currency, 'GBP') AS currency,
+                   d.total_value      AS total_value,
+                   d.cost_basis       AS cost_basis,
+                   COALESCE(d.fx_rate_to_base, 1.0) AS fx_rate_to_base,
+                   d.valuation_date AS snapshot_date
+              FROM daily_account_valuation d
+              JOIN accounts a ON a.id = d.account_id
+             WHERE d.valuation_date = :as_of
+        """), {"as_of": target})).mappings().all()
+
+    out: list[dict[str, Any]] = []
+    for r in rows:
+        snapshot_date = (r["snapshot_date"] if isinstance(r["snapshot_date"], date) else
+                         date.fromisoformat(str(r["snapshot_date"])))
+        total_value = Decimal(str(r["total_value"] or 0))
+        fx = Decimal(str(r["fx_rate_to_base"]))
+        market_value_gbp = (total_value * fx).quantize(_TWO_PLACES, rounding=ROUND_HALF_EVEN)
+        cost_basis_gbp: Decimal | None = None
+        if r["cost_basis"] is not None:
+            cost_basis_gbp = (Decimal(str(r["cost_basis"])) *
+                              fx).quantize(_TWO_PLACES, rounding=ROUND_HALF_EVEN)
+        out.append({
+            "external_id": f"wealthfolio:{r['account_id']}:{snapshot_date.isoformat()}",
+            "snapshot_date": snapshot_date,
+            "account_id": str(r["account_id"]),
+            "account_name": r["account_name"] or "",
+            "account_type": r["account_type"] or "unknown",
+            "currency": r["currency"] or "GBP",
+            "market_value": total_value,
+            "market_value_gbp": market_value_gbp,
+            "cost_basis_gbp": cost_basis_gbp,
+        })
+    return out