fix: corrigir memory leaks e testes de mocks

- Fechar ConvexClient antigo antes de criar novo (evita memory leak)
- Adicionar flag disposed para prevenir race condition em useEffect
- Reduzir polling SSE de 1s para 5s (balanco entre responsividade e carga)
- Adicionar .take() aos mocks de testes para compatibilidade

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

tests/utils/report-test-helpers.ts

@@ -31,6 +31,7 @@ function ticketsChain(collection: Doc<"tickets">[]) {
     }),
     order: vi.fn(() => chain),
     collect: vi.fn(async () => collection),
+    take: vi.fn(async (limit: number) => collection.slice(0, limit)),
   }
   return chain
 }
@@ -74,9 +75,11 @@ export function createReportsCtx({
             cb?.(noopIndexBuilder)
             return {
               collect: vi.fn(async () => queues),
+              take: vi.fn(async (limit: number) => queues.slice(0, limit)),
             }
           }),
           collect: vi.fn(async () => queues),
+          take: vi.fn(async (limit: number) => queues.slice(0, limit)),
         }
       }
 
@@ -86,9 +89,11 @@ export function createReportsCtx({
             cb?.(noopIndexBuilder)
             return {
               collect: vi.fn(async () => categories),
+              take: vi.fn(async (limit: number) => categories.slice(0, limit)),
             }
           }),
           collect: vi.fn(async () => categories),
+          take: vi.fn(async (limit: number) => categories.slice(0, limit)),
         }
       }
 
@@ -103,8 +108,10 @@ export function createReportsCtx({
               },
             }
             cb?.(builder as { eq: (field: unknown, value: unknown) => unknown })
+            const events = ticketId ? ticketEventsByTicket.get(ticketId) ?? [] : []
             return {
-              collect: vi.fn(async () => (ticketId ? ticketEventsByTicket.get(ticketId) ?? [] : [])),
+              collect: vi.fn(async () => events),
+              take: vi.fn(async (limit: number) => events.slice(0, limit)),
             }
           }),
         }
@@ -121,8 +128,10 @@ export function createReportsCtx({
               },
             }
             cb?.(builder as { eq: (field: unknown, value: unknown) => unknown })
+            const sessions = agentId ? ticketWorkSessionsByAgent.get(agentId) ?? [] : []
             return {
-              collect: vi.fn(async () => (agentId ? ticketWorkSessionsByAgent.get(agentId) ?? [] : [])),
+              collect: vi.fn(async () => sessions),
+              take: vi.fn(async (limit: number) => sessions.slice(0, limit)),
             }
           }),
         }
@@ -131,8 +140,10 @@ export function createReportsCtx({
       return {
         withIndex: vi.fn(() => ({
           collect: vi.fn(async () => []),
+          take: vi.fn(async () => []),
         })),
         collect: vi.fn(async () => []),
+        take: vi.fn(async () => []),
       }
     }),
   }