feat: resolve observer project page round default and add selector

The observer full project page used to call getProjectDetail without
a round, getting cross-round contaminated stats. It now resolves a
default — the currently OPEN round the project is in, falling back
to the most recently CLOSED one — and renders a selector chip in
the score card whenever the project participated in more than one
candidate round. Initial selection respects the ?round= query param.

A new observer procedure (getProjectRoundsForObserver) returns the
project's open or closed rounds for the picker.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/server/routers/analytics.ts

@@ -2187,6 +2187,26 @@ export const analyticsRouter = router({
       }
     }),
 
+  /**
+   * Returns rounds the project has participated in, restricted to those that
+   * are open or already closed. Used by the observer full project page to
+   * resolve a default round when none is specified in the URL.
+   */
+  getProjectRoundsForObserver: observerProcedure
+    .input(z.object({ projectId: z.string() }))
+    .query(async ({ ctx, input }) => {
+      const states = await ctx.prisma.projectRoundState.findMany({
+        where: { projectId: input.projectId },
+        select: {
+          round: { select: { id: true, name: true, status: true, sortOrder: true } },
+        },
+      })
+      return states
+        .map((s) => s.round)
+        .filter((r) => r.status === 'ROUND_ACTIVE' || r.status === 'ROUND_CLOSED')
+        .sort((a, b) => a.sortOrder - b.sortOrder)
+    }),
+
   getRecentFiles: observerProcedure
     .input(z.object({ roundId: z.string(), limit: z.number().min(1).max(50).default(10) }))
     .query(async ({ ctx, input }) => {