Add team management frontend

- New /dashboard/team page with inline team name editing, slug/ID copy,
  members table with split-button (remove + make admin/member), add member
  typeahead, and danger zone (delete/leave) with confirmation dialogs
- Sidebar now fetches real teams from API, supports team switching and
  team creation via dialog
- Rename nav item Members → Team, route /dashboard/members → /dashboard/team
- New src/lib/api/team.ts with typed functions for all team endpoints

frontend/src/lib/api/team.ts

@@ -0,0 +1,83 @@
+import { apiFetch, type ApiResult } from '$lib/api/client';
+
+export type TeamMember = {
+	user_id: string;
+	email: string;
+	role: 'owner' | 'admin' | 'member';
+	joined_at: string;
+};
+
+export type TeamInfo = {
+	id: string;
+	name: string;
+	slug: string;
+	created_at: string;
+};
+
+export type TeamDetail = {
+	team: TeamInfo;
+	members: TeamMember[];
+};
+
+export type UserSearchResult = {
+	user_id: string;
+	email: string;
+};
+
+export type TeamWithRole = {
+	id: string;
+	name: string;
+	slug: string;
+	created_at: string;
+	role: string;
+};
+
+export async function listTeams(): Promise<ApiResult<TeamWithRole[]>> {
+	return apiFetch('GET', '/api/v1/teams');
+}
+
+export async function createTeam(name: string): Promise<ApiResult<TeamWithRole>> {
+	return apiFetch('POST', '/api/v1/teams', { name });
+}
+
+export async function switchTeam(
+	teamId: string
+): Promise<ApiResult<{ token: string; user_id: string; team_id: string; email: string }>> {
+	return apiFetch('POST', '/api/v1/auth/switch-team', { team_id: teamId });
+}
+
+export async function getTeam(id: string): Promise<ApiResult<TeamDetail>> {
+	return apiFetch('GET', `/api/v1/teams/${id}`);
+}
+
+export async function updateTeam(id: string, name: string): Promise<ApiResult<void>> {
+	return apiFetch('PATCH', `/api/v1/teams/${id}`, { name });
+}
+
+export async function addMember(id: string, email: string): Promise<ApiResult<TeamMember>> {
+	return apiFetch('POST', `/api/v1/teams/${id}/members`, { email });
+}
+
+export async function removeMember(id: string, userId: string): Promise<ApiResult<void>> {
+	return apiFetch('DELETE', `/api/v1/teams/${id}/members/${userId}`);
+}
+
+export async function updateMemberRole(
+	id: string,
+	userId: string,
+	role: 'admin' | 'member'
+): Promise<ApiResult<void>> {
+	return apiFetch('PATCH', `/api/v1/teams/${id}/members/${userId}`, { role });
+}
+
+export async function deleteTeam(id: string): Promise<ApiResult<void>> {
+	return apiFetch('DELETE', `/api/v1/teams/${id}`);
+}
+
+export async function leaveTeam(id: string): Promise<ApiResult<void>> {
+	return apiFetch('POST', `/api/v1/teams/${id}/leave`);
+}
+
+export async function searchUsers(email: string): Promise<ApiResult<UserSearchResult[]>> {
+	return apiFetch('GET', `/api/v1/users/search?email=${encodeURIComponent(email)}`);
+}