rename: "Team" billing tier to "Family"

All literal "team" tier-value references renamed to "family" across
API routes, admin UI, OpenAPI schemas, and lib/tiers.ts. The DB enum
value itself is renamed in place via ALTER TYPE ... RENAME VALUE
(migration 0044) rather than drizzle-kit's auto-generated
drop-and-recreate-the-enum migration, which would have failed against
any existing row still holding 'team' — RENAME VALUE preserves
existing data with no cast/backfill needed.

Also adds STRIPE_PLAN.md — a full Stripe billing integration plan
(Checkout+Portal, tier→Price mapping, admin billing dashboard, and a
multi-user Family-group design since Family is meant to cover several
accounts under one subscription, not one payer). Planning only, no
Stripe code yet.

v0.47.0

apps/web/app/api/v1/admin/invites/route.ts

@@ -5,7 +5,7 @@ import { createInvite, listInvites } from "@/lib/invites";
 import { randomUUID } from "crypto";
 
 const VALID_ROLES = ["user", "moderator", "admin"] as const;
-const VALID_TIERS = ["free", "pro", "team"] as const;
+const VALID_TIERS = ["free", "pro", "family"] as const;
 
 export async function GET() {
   const { response } = await requireAdmin();

apps/web/app/api/v1/admin/tiers/[tier]/route.ts

@@ -16,7 +16,7 @@ export async function PATCH(req: NextRequest, { params }: RouteContext) {
   if (response) return response;
 
   const { tier } = await params;
-  if (tier !== "free" && tier !== "pro" && tier !== "team") {
+  if (tier !== "free" && tier !== "pro" && tier !== "family") {
     return NextResponse.json({ error: "Invalid tier" }, { status: 400 });
   }
 

apps/web/app/api/v1/admin/users/[id]/route.ts

@@ -16,7 +16,7 @@ export async function PATCH(req: NextRequest, { params }: RouteContext) {
   const { role, tier } = body;
 
   const validRoles = ["user", "moderator", "admin"] as const;
-  const validTiers = ["free", "pro", "team"] as const;
+  const validTiers = ["free", "pro", "family"] as const;
 
   if (role !== undefined && !validRoles.includes(role as typeof validRoles[number])) {
     return NextResponse.json({ error: "Invalid role" }, { status: 400 });
@@ -25,11 +25,11 @@ export async function PATCH(req: NextRequest, { params }: RouteContext) {
     return NextResponse.json({ error: "Invalid tier" }, { status: 400 });
   }
 
-  const updateData: Partial<{ role: "user" | "moderator" | "admin"; tier: "free" | "pro" | "team"; updatedAt: Date }> = {
+  const updateData: Partial<{ role: "user" | "moderator" | "admin"; tier: "free" | "pro" | "family"; updatedAt: Date }> = {
     updatedAt: new Date(),
   };
   if (role) updateData.role = role as "user" | "moderator" | "admin";
-  if (tier) updateData.tier = tier as "free" | "pro" | "team";
+  if (tier) updateData.tier = tier as "free" | "pro" | "family";
 
   const [updated] = await db
     .update(users)

apps/web/app/api/v1/admin/users/route.ts

@@ -7,7 +7,7 @@ import { randomBytes, randomUUID } from "crypto";
 import { APIError } from "better-auth";
 
 const VALID_ROLES = ["user", "moderator", "admin"] as const;
-const VALID_TIERS = ["free", "pro", "team"] as const;
+const VALID_TIERS = ["free", "pro", "family"] as const;
 
 export async function POST(req: NextRequest) {
   const { session, response } = await requireAdmin();