Initial commit: MyMidas personal finance tracker

Full-stack self-hosted finance app with FastAPI backend and React frontend.

Features:
- Accounts, transactions, budgets, investments with GBP base currency
- CSV import with auto-detection for 10 UK bank formats
- ML predictions: spending forecast, net worth projection, Monte Carlo
- 7 selectable themes (Obsidian, Arctic, Midnight, Vault, Terminal, Synthwave, Ledger)
- Receipt/document attachments on transactions (JPEG, PNG, WebP, PDF)
- AES-256-GCM field encryption, RS256 JWT, TOTP 2FA, RLS, audit log
- Encrypted nightly backups + key rotation script
- Mobile-responsive layout with bottom nav

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/workers/fx_sync.py

@@ -0,0 +1,74 @@
+import structlog
+
+logger = structlog.get_logger()
+
+PAIRS = [
+    ("GBP", "USD"), ("GBP", "EUR"), ("GBP", "JPY"), ("GBP", "CAD"),
+    ("GBP", "AUD"), ("GBP", "CHF"), ("USD", "GBP"), ("EUR", "GBP"),
+]
+
+
+async def fx_sync_job() -> None:
+    from app.dependencies import get_session_factory
+    session_factory = get_session_factory()
+    if not session_factory:
+        return
+
+    try:
+        import requests
+        r = requests.get(
+            "https://api.exchangerate-api.com/v4/latest/GBP",
+            timeout=10,
+        )
+        r.raise_for_status()
+        data = r.json()
+        rates = data.get("rates", {})
+    except Exception as exc:
+        logger.error("fx_fetch_failed", error=str(exc))
+        return
+
+    from datetime import datetime, timezone
+    from decimal import Decimal
+    import uuid as _uuid
+    from sqlalchemy import select
+    from app.db.models.currency import ExchangeRate  # type: ignore[attr-defined]
+
+    async with session_factory() as db:
+        try:
+            now = datetime.now(timezone.utc)
+            for base, quote in PAIRS:
+                if base == "GBP":
+                    rate_val = rates.get(quote)
+                else:
+                    gbp_to_base = rates.get(base)
+                    if not gbp_to_base or gbp_to_base == 0:
+                        continue
+                    rate_val = 1 / gbp_to_base
+
+                if not rate_val:
+                    continue
+
+                result = await db.execute(
+                    select(ExchangeRate).where(
+                        ExchangeRate.base_currency == base,
+                        ExchangeRate.quote_currency == quote,
+                    )
+                )
+                existing = result.scalar_one_or_none()
+                if existing:
+                    existing.rate = Decimal(str(round(rate_val, 8)))
+                    existing.fetched_at = now
+                else:
+                    db.add(ExchangeRate(
+                        id=_uuid.uuid4(),
+                        base_currency=base,
+                        quote_currency=quote,
+                        rate=Decimal(str(round(rate_val, 8))),
+                        source="exchangerate-api",
+                        fetched_at=now,
+                    ))
+            await db.commit()
+            logger.info("fx_sync_done", pairs=len(PAIRS))
+        except Exception as exc:
+            await db.rollback()
+            logger.error("fx_sync_db_failed", error=str(exc))