feat(members): implement /members page — Kachel-Ansicht (E2, issue #48)

Backend:
- Rename V006 migration to V026 (avoid conflict with existing V006)
- Migration adds invalidated_at + partial unique index on household_invite

Frontend:
- Toast.svelte — new system component (message + dismiss)
- SegmentedControl.svelte — new system component (options, value, onchange)
- members/+page.server.ts — loads members + active invite
- members/[userId]/+server.ts — DELETE/PATCH proxy
- members/invites/+server.ts — POST (regenerate) proxy
- MemberCard.svelte — tile with avatar, kebab, inline role edit
- RemoveDialog.svelte — confirmation dialog (desktop modal + BottomSheet mobile)
- InviteCard.svelte + InvitePanel.svelte — invite management UI
- MemberGrid.svelte — responsive 4/2-col grid with sorted members
- members/+page.svelte — page composing all components with optimistic updates

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

frontend/src/routes/(app)/members/MemberCard.test.ts

@@ -0,0 +1,147 @@
+import { describe, it, expect, vi } from 'vitest';
+import { render, screen } from '@testing-library/svelte';
+import userEvent from '@testing-library/user-event';
+import MemberCard from './MemberCard.svelte';
+
+const plannerMember = {
+	userId: 'u1',
+	displayName: 'Sarah',
+	role: 'planner',
+	joinedAt: '2024-01-01T00:00:00Z'
+};
+
+const regularMember = {
+	userId: 'u2',
+	displayName: 'Tom',
+	role: 'member',
+	joinedAt: '2024-02-01T00:00:00Z'
+};
+
+describe('MemberCard', () => {
+	it('shows the member display name', () => {
+		render(MemberCard, {
+			props: {
+				member: plannerMember,
+				isCurrentUser: false,
+				isPlanner: false,
+				onremove: vi.fn(),
+				onrolechange: vi.fn()
+			}
+		});
+		expect(screen.getByText('Sarah')).toBeInTheDocument();
+	});
+
+	it('shows "Du"-badge when isCurrentUser is true', () => {
+		render(MemberCard, {
+			props: {
+				member: plannerMember,
+				isCurrentUser: true,
+				isPlanner: false,
+				onremove: vi.fn(),
+				onrolechange: vi.fn()
+			}
+		});
+		expect(screen.getByText('Du')).toBeInTheDocument();
+	});
+
+	it('does not show kebab button when isCurrentUser is true', () => {
+		render(MemberCard, {
+			props: {
+				member: plannerMember,
+				isCurrentUser: true,
+				isPlanner: true,
+				onremove: vi.fn(),
+				onrolechange: vi.fn()
+			}
+		});
+		expect(screen.queryByTestId('kebab-btn')).toBeNull();
+	});
+
+	it('does not show kebab button when viewer is not a planner', () => {
+		render(MemberCard, {
+			props: {
+				member: regularMember,
+				isCurrentUser: false,
+				isPlanner: false,
+				onremove: vi.fn(),
+				onrolechange: vi.fn()
+			}
+		});
+		expect(screen.queryByTestId('kebab-btn')).toBeNull();
+	});
+
+	it('shows kebab button for other members when viewer is planner', () => {
+		render(MemberCard, {
+			props: {
+				member: regularMember,
+				isCurrentUser: false,
+				isPlanner: true,
+				onremove: vi.fn(),
+				onrolechange: vi.fn()
+			}
+		});
+		expect(screen.getByTestId('kebab-btn')).toBeInTheDocument();
+	});
+
+	it('opens dropdown when kebab is clicked', async () => {
+		render(MemberCard, {
+			props: {
+				member: regularMember,
+				isCurrentUser: false,
+				isPlanner: true,
+				onremove: vi.fn(),
+				onrolechange: vi.fn()
+			}
+		});
+		await userEvent.click(screen.getByTestId('kebab-btn'));
+		expect(screen.getByText('Rolle ändern')).toBeInTheDocument();
+		expect(screen.getByText('Entfernen')).toBeInTheDocument();
+	});
+
+	it('calls onremove when "Entfernen" is clicked in dropdown', async () => {
+		const onremove = vi.fn();
+		render(MemberCard, {
+			props: {
+				member: regularMember,
+				isCurrentUser: false,
+				isPlanner: true,
+				onremove,
+				onrolechange: vi.fn()
+			}
+		});
+		await userEvent.click(screen.getByTestId('kebab-btn'));
+		await userEvent.click(screen.getByText('Entfernen'));
+		expect(onremove).toHaveBeenCalledWith(regularMember);
+	});
+
+	it('shows SegmentedControl when "Rolle ändern" is clicked', async () => {
+		render(MemberCard, {
+			props: {
+				member: regularMember,
+				isCurrentUser: false,
+				isPlanner: true,
+				onremove: vi.fn(),
+				onrolechange: vi.fn()
+			}
+		});
+		await userEvent.click(screen.getByTestId('kebab-btn'));
+		await userEvent.click(screen.getByText('Rolle ändern'));
+		expect(screen.getByRole('group')).toBeInTheDocument();
+	});
+
+	it('closes dropdown on Escape key', async () => {
+		render(MemberCard, {
+			props: {
+				member: regularMember,
+				isCurrentUser: false,
+				isPlanner: true,
+				onremove: vi.fn(),
+				onrolechange: vi.fn()
+			}
+		});
+		await userEvent.click(screen.getByTestId('kebab-btn'));
+		expect(screen.getByText('Entfernen')).toBeInTheDocument();
+		await userEvent.keyboard('{Escape}');
+		expect(screen.queryByText('Entfernen')).toBeNull();
+	});
+});