Add USB policy improvements and emprestimos details modal

- Add cron job to cleanup stale pending USB policies every 30 min
- Add cleanupStalePendingPolicies mutation to usbPolicy.ts
- Add USB policy fields to machines listByTenant query
- Display USB status chip in device details and bulk control modal
- Add details modal for emprestimos with all loan information
- Add observacoesDevolucao field to preserve original observations
- Fix status text size in details modal title

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

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

convex/usbPolicy.ts

@@ -249,3 +249,54 @@ export const bulkSetUsbPolicy = mutation({
     return { results, total: args.machineIds.length, successful: results.filter((r) => r.success).length }
   },
 })
+
+/**
+ * Cleanup de policies USB pendentes por mais de 1 hora.
+ * Marca como FAILED com mensagem de timeout.
+ */
+export const cleanupStalePendingPolicies = mutation({
+  args: {
+    staleThresholdMs: v.optional(v.number()),
+  },
+  handler: async (ctx, args) => {
+    const thresholdMs = args.staleThresholdMs ?? 3600000 // 1 hora por padrao
+    const now = Date.now()
+    const cutoff = now - thresholdMs
+
+    // Buscar maquinas com status PENDING e appliedAt antigo
+    const allMachines = await ctx.db.query("machines").collect()
+    const staleMachines = allMachines.filter(
+      (m) =>
+        m.usbPolicyStatus === "PENDING" &&
+        m.usbPolicyAppliedAt !== undefined &&
+        m.usbPolicyAppliedAt < cutoff
+    )
+
+    let cleaned = 0
+    for (const machine of staleMachines) {
+      await ctx.db.patch(machine._id, {
+        usbPolicyStatus: "FAILED",
+        usbPolicyError: "Timeout: Agent nao reportou status apos 1 hora. Verifique se o agent esta ativo.",
+        updatedAt: now,
+      })
+
+      // Atualizar evento correspondente
+      const latestEvent = await ctx.db
+        .query("usbPolicyEvents")
+        .withIndex("by_machine_created", (q) => q.eq("machineId", machine._id))
+        .order("desc")
+        .first()
+
+      if (latestEvent && latestEvent.status === "PENDING") {
+        await ctx.db.patch(latestEvent._id, {
+          status: "FAILED",
+          error: "Timeout automatico",
+        })
+      }
+
+      cleaned++
+    }
+
+    return { cleaned, checked: allMachines.length }
+  },
+})