refactor: massive codebase stabilization, strict TS, UI/UX overhaul, and central logging

client/src/types/auth.ts

@@ -0,0 +1,6 @@
+export type AuthContextType = {
+  token: string | null;
+  isAuthenticated: boolean;
+  login: (token: string) => void;
+  logout: () => void;
+};

client/src/types/theme.ts

@@ -0,0 +1,6 @@
+export type ColorMode = 'light' | 'dark' | 'system';
+
+export type ThemeContextType = {
+  mode: ColorMode;
+  toggleColorMode: () => void;
+};