fix(task): Filter out decompose container tasks from phase and initiative task lists

Decompose tasks are parent containers whose children inherit the same phaseId,
causing both the container and its children to appear in task listings.

src/trpc/routers/task.ts

@@ -131,14 +131,16 @@ export function taskProcedures(publicProcedure: ProcedureBuilder) {
       .input(z.object({ initiativeId: z.string().min(1) }))
       .query(async ({ ctx, input }) => {
         const taskRepository = requireTaskRepository(ctx);
-        return taskRepository.findByInitiativeId(input.initiativeId);
+        const tasks = await taskRepository.findByInitiativeId(input.initiativeId);
+        return tasks.filter((t) => t.category !== 'decompose');
       }),
 
     listPhaseTasks: publicProcedure
       .input(z.object({ phaseId: z.string().min(1) }))
       .query(async ({ ctx, input }) => {
         const taskRepository = requireTaskRepository(ctx);
-        return taskRepository.findByPhaseId(input.phaseId);
+        const tasks = await taskRepository.findByPhaseId(input.phaseId);
+        return tasks.filter((t) => t.category !== 'decompose');
       }),
 
     approveTask: publicProcedure