Decouple projects from rounds with RoundProject join table

Projects now exist at the program level instead of being locked to a
single round. A new RoundProject join table enables many-to-many
relationships with per-round status tracking. Rounds have sortOrder
for configurable progression paths.

- Add RoundProject model, programId on Project, sortOrder on Round
- Migration preserves existing data (roundId -> RoundProject entries)
- Update all routers to query through RoundProject join
- Add assign/remove/advance/reorder round endpoints
- Add Assign, Advance, Remove Projects dialogs on round detail page
- Add round reorder controls (up/down arrows) on rounds list
- Show all rounds on project detail page

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/server/routers/notion-import.ts

@@ -171,9 +171,9 @@ export const notionImportRouter = router({
           }
 
           // Create project
-          await ctx.prisma.project.create({
+          const createdProject = await ctx.prisma.project.create({
             data: {
-              roundId: round.id,
+              programId: round.programId,
               title: title.trim(),
               teamName: typeof teamName === 'string' ? teamName.trim() : null,
               description: typeof description === 'string' ? description : null,
@@ -183,6 +183,14 @@ export const notionImportRouter = router({
                 notionPageId: record.id,
                 notionDatabaseId: input.databaseId,
               } as Prisma.InputJsonValue,
+            },
+          })
+
+          // Create RoundProject entry
+          await ctx.prisma.roundProject.create({
+            data: {
+              roundId: round.id,
+              projectId: createdProject.id,
               status: 'SUBMITTED',
             },
           })