feat: implement variable team matchups with partner rotation

- Add manual team entry for permanent teams in Matchups tab
- Rename 'Teams' tab to 'Matchups' for clarity
- Implement partner rotation strategies (minimize_repeat, maximize_even, elo_based)
- Track partnerships across rounds to minimize repeat pairings
- Fix unit tests for team configuration and ELO calculations
- Add E2E test for 9+ participant tournaments with variable matchups

Key changes:
- TeamsSection.tsx: Added router.refresh(), manual team entry, and matchup display
- schedule-generator.ts: Enhanced generateVariableRoundRobin to track partnerships
- team-generator.ts: Fixed partnership frequency tracking across rounds
- API routes: Updated to support variable team durability with rotation strategies

src/app/api/tournaments/[id]/route.ts

@@ -3,18 +3,12 @@ import { prisma } from "@/lib/prisma";
 import { canManageTournament, canDeleteTournament } from "@/lib/permissions";
 import { getTournamentStatus } from "@/lib/tournamentUtils";
 
-interface RouteParams {
-  params: Promise<{
-    id: string;
-  }>;
-}
-
 /**
  * GET /api/tournaments/[id]
  * 
  * Get a single tournament by ID
  */
-export async function GET(request: Request, { params }: RouteParams) {
+export async function GET(request: Request, { params }: { params: Promise<{ id: string }> }) {
   try {
     const { id } = await params
     const tournamentId = parseInt(id);
@@ -90,7 +84,7 @@ export async function GET(request: Request, { params }: RouteParams) {
  * 
  * Update a tournament by ID
  */
-export async function PUT(request: Request, { params }: RouteParams) {
+export async function PUT(request: Request, { params }: { params: Promise<{ id: string }> }) {
   try {
     const { id } = await params
     const tournamentId = parseInt(id);
@@ -215,7 +209,7 @@ export async function PUT(request: Request, { params }: RouteParams) {
  *   - deleteMatches: Delete all matches associated with the tournament
  *   - orphanMatches: Keep matches but remove tournament association (eventId becomes null)
  */
-export async function DELETE(request: Request, { params }: RouteParams) {
+export async function DELETE(request: Request, { params }: { params: Promise<{ id: string }> }) {
   try {
     const { id } = await params
     const tournamentId = parseInt(id);