Fix 5 code review issues in sport-based template conversion

- Migration (0114): TRUNCATE season_template_sports before adding NOT NULL sport_id
  column to prevent failure on non-empty tables
- findDraftableSportsSeasonBySportId: add orderBy(year DESC, draftOn DESC) so the
  newest season is returned deterministically when multiple draft windows overlap
- leagues/new.tsx loader: build a Map from the already-fetched allSportsSeasons
  instead of firing N×M per-sport DB queries (eliminates ~30 redundant queries)
- schema: add UNIQUE(templateId, sportId) on season_template_sports to prevent
  duplicate sport entries via concurrent requests
- schema: add UNIQUE(name) on season_templates so import merge-mode lookup by
  name is unambiguous (migration 0115)

https://claude.ai/code/session_01CoRLHERakMncbPs877izvw

app/models/sports-season.ts

@@ -162,6 +162,7 @@ export async function findDraftableSportsSeasonBySportId(sportId: string) {
         gte(ss.draftOff, today),
         isNull(ss.fantasySeasonId)
       ),
+    orderBy: (ss, { desc }) => [desc(ss.year), desc(ss.draftOn)],
     with: {
       sport: true,
     },

app/routes/leagues/new.tsx

@@ -11,7 +11,7 @@ import { createSeason } from "~/models/season";
 import { linkMultipleSportsToSeason } from "~/models/season-sport";
 import { createManyTeams } from "~/models/team";
 import { findActiveSeasonTemplates, findSeasonTemplateWithSports } from "~/models/season-template";
-import { findDraftableSportsSeasons, findDraftableSportsSeasonBySportId } from "~/models/sports-season";
+import { findDraftableSportsSeasons } from "~/models/sports-season";
 import { findUserById, updateUser } from "~/models/user";
 import { generateUniqueTeamNames, prependOwnerToTeamName } from "~/utils/team-names";
 import { format } from "date-fns";
@@ -103,19 +103,18 @@ export async function loader(args: Route.LoaderArgs) {
   const templates = await findActiveSeasonTemplates();
   const allSportsSeasons = await findDraftableSportsSeasons();
 
+  const draftableSeasonBySportId = new Map(
+    allSportsSeasons.map((s) => [s.sportId, s])
+  );
+
   const templatesWithSports = await Promise.all(
     templates.map(async (template) => {
       const t = await findSeasonTemplateWithSports(template.id);
-      const resolvedSeasons = await Promise.all(
-        (t?.seasonTemplateSports ?? []).map((ts: { sportId: string }) =>
-          findDraftableSportsSeasonBySportId(ts.sportId)
-        )
-      );
       return {
         ...template,
-        sportsSeasonIds: resolvedSeasons
-          .filter((s): s is NonNullable<typeof s> => s != null)
-          .map((s) => s.id),
+        sportsSeasonIds: (t?.seasonTemplateSports ?? [])
+          .map((ts: { sportId: string }) => draftableSeasonBySportId.get(ts.sportId)?.id)
+          .filter((id): id is string => id != null),
       };
     })
   );

database/schema.ts

@@ -193,7 +193,9 @@ export const seasonTemplates = pgTable("season_templates", {
   isActive: boolean("is_active").notNull().default(true),
   createdAt: timestamp("created_at").defaultNow().notNull(),
   updatedAt: timestamp("updated_at").defaultNow().notNull(),
-});
+}, (t) => ({
+  uniqueName: uniqueIndex("season_templates_name_unique").on(t.name),
+}));
 
 export const seasons = pgTable("seasons", {
   id: uuid("id").primaryKey().defaultRandom(),
@@ -570,7 +572,9 @@ export const seasonTemplateSports = pgTable("season_template_sports", {
     .notNull()
     .references(() => sports.id, { onDelete: "cascade" }),
   createdAt: timestamp("created_at").defaultNow().notNull(),
-});
+}, (t) => ({
+  uniqueTemplateSport: uniqueIndex("season_template_sports_template_sport_unique").on(t.templateId, t.sportId),
+}));
 
 export const seasonSports = pgTable("season_sports", {
   id: uuid("id").primaryKey().defaultRandom(),

drizzle/0114_warm_swarm.sql

@@ -1,3 +1,5 @@
+TRUNCATE TABLE "season_template_sports";
+--> statement-breakpoint
 ALTER TABLE "season_template_sports" DROP CONSTRAINT "season_template_sports_sports_season_id_sports_seasons_id_fk";
 --> statement-breakpoint
 ALTER TABLE "season_template_sports" ADD COLUMN "sport_id" uuid NOT NULL;--> statement-breakpoint

drizzle/0115_spooky_spot.sql

@@ -0,0 +1,2 @@
+CREATE UNIQUE INDEX IF NOT EXISTS "season_template_sports_template_sport_unique" ON "season_template_sports" USING btree ("template_id","sport_id");--> statement-breakpoint
+CREATE UNIQUE INDEX IF NOT EXISTS "season_templates_name_unique" ON "season_templates" USING btree ("name");

drizzle/meta/_journal.json

@@ -806,6 +806,13 @@
       "when": 1780595525976,
       "tag": "0114_warm_swarm",
       "breakpoints": true
+    },
+    {
+      "idx": 115,
+      "version": "7",
+      "when": 1780596702982,
+      "tag": "0115_spooky_spot",
+      "breakpoints": true
     }
   ]
 }