feat: theme dropdown with system preference and comprehensive bottle-type fixes (#138)

- Replace dark/light toggle with Light/Dark/System dropdown menu
- System theme follows OS prefers-color-scheme setting
- Apply theme dropdown to shared schedule page
- Fix 7 packageType (bottle) bugs across stock calc, share, refills, export/import
- Fix planner bottle-type stock calculation and display
- Fix dailyRate double-counting with per-intake takenBy
- Fix About modal update check stale caching
- Fix intake reminder past-intake seeding and push title
- Fix phantom DB path in drizzle.config.ts
- Fix mobile dose field visibility
- Make medication name clickable in dashboard reminder bar
- Improve planner checkbox UX with inline tooltip
- Add 20+ new tests covering all fixes

frontend/src/test/components/AppHeader.test.tsx

@@ -82,7 +82,7 @@ describe("AppHeader", () => {
 		});
 	});
 
-	it("renders theme toggle button", async () => {
+	it("renders theme menu button", async () => {
 		const mockOnOpenProfile = vi.fn();
 		const mockOnOpenAbout = vi.fn();
 
@@ -95,12 +95,33 @@ describe("AppHeader", () => {
 		);
 
 		await waitFor(() => {
-			const buttons = screen.getAllByRole("button");
-			const themeBtn = buttons.find((btn) => btn.textContent?.includes("🌙") || btn.textContent?.includes("☀️"));
+			const themeBtn = screen.getByTitle(/theme\.title/i);
 			expect(themeBtn).toBeInTheDocument();
 		});
 	});
 
+	it("opens theme dropdown and shows Light/Dark/System options", async () => {
+		const mockOnOpenProfile = vi.fn();
+		const mockOnOpenAbout = vi.fn();
+
+		render(
+			<MemoryRouter initialEntries={["/dashboard"]}>
+				<AuthProvider>
+					<AppHeader onOpenProfile={mockOnOpenProfile} onOpenAbout={mockOnOpenAbout} />
+				</AuthProvider>
+			</MemoryRouter>
+		);
+
+		await waitFor(() => {
+			const themeBtn = screen.getByTitle(/theme\.title/i);
+			fireEvent.click(themeBtn);
+		});
+
+		expect(screen.getByText(/theme\.light/i)).toBeInTheDocument();
+		expect(screen.getByText(/theme\.dark/i)).toBeInTheDocument();
+		expect(screen.getByText(/theme\.system/i)).toBeInTheDocument();
+	});
+
 	it("renders settings button when auth is disabled", async () => {
 		const mockOnOpenProfile = vi.fn();
 		const mockOnOpenAbout = vi.fn();