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>

frontend/src/store/uiStore.ts

@@ -0,0 +1,34 @@
+import { create } from "zustand";
+import { persist } from "zustand/middleware";
+
+export type Theme =
+  | "obsidian"
+  | "arctic"
+  | "midnight"
+  | "vault"
+  | "terminal"
+  | "synthwave"
+  | "ledger";
+
+interface UiState {
+  theme: Theme;
+  sidebarOpen: boolean;
+  currency: string;
+  setTheme: (t: Theme) => void;
+  setSidebarOpen: (v: boolean) => void;
+  setCurrency: (c: string) => void;
+}
+
+export const useUiStore = create<UiState>()(
+  persist(
+    (set) => ({
+      theme: "obsidian",
+      sidebarOpen: true,
+      currency: "GBP",
+      setTheme: (theme) => set({ theme }),
+      setSidebarOpen: (v) => set({ sidebarOpen: v }),
+      setCurrency: (c) => set({ currency: c }),
+    }),
+    { name: "finance-ui" }
+  )
+);