feat(desktop): add file attachments and native chat window

- Add file upload support in chat (PDF, images, txt, docs, xlsx)
  - Limited to 10MB max file size
  - Only allowed extensions for security
- Use native Windows decorations for chat window
- Remove ChatFloatingWidget (replaced by native window)
- Simplify chat event listeners (window managed by Rust)
- Fix typo "sessao" -> "sessão"

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

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

convex/liveChat.ts

@@ -1,6 +1,7 @@
 import { v } from "convex/values"
-import { mutation, query, type MutationCtx, type QueryCtx } from "./_generated/server"
+import { action, mutation, query, type MutationCtx, type QueryCtx } from "./_generated/server"
 import { ConvexError } from "convex/values"
+import { api } from "./_generated/api"
 import type { Doc, Id } from "./_generated/dataModel"
 import { sha256 } from "@noble/hashes/sha256"
 import { bytesToHex as toHex } from "@noble/hashes/utils"
@@ -690,3 +691,94 @@ export const getTicketChatHistory = query({
     }
   },
 })
+
+// ============================================
+// UPLOAD DE ARQUIVOS (Maquina/Cliente)
+// ============================================
+
+// Tipos de arquivo permitidos para upload
+const ALLOWED_MIME_TYPES = [
+  // Imagens
+  "image/jpeg",
+  "image/png",
+  "image/gif",
+  "image/webp",
+  // Documentos
+  "application/pdf",
+  "text/plain",
+  "application/msword",
+  "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+  "application/vnd.ms-excel",
+  "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+]
+
+const ALLOWED_EXTENSIONS = [
+  ".jpg", ".jpeg", ".png", ".gif", ".webp",
+  ".pdf", ".txt", ".doc", ".docx", ".xls", ".xlsx",
+]
+
+// Tamanho maximo: 10MB
+const MAX_FILE_SIZE = 10 * 1024 * 1024
+
+// Mutation interna para validar token (usada pela action)
+export const validateMachineTokenForUpload = query({
+  args: { machineToken: v.string() },
+  handler: async (ctx, args) => {
+    const tokenHash = hashToken(args.machineToken)
+    const tokenRecord = await ctx.db
+      .query("machineTokens")
+      .withIndex("by_token_hash", (q) => q.eq("tokenHash", tokenHash))
+      .first()
+
+    if (!tokenRecord) {
+      return { valid: false }
+    }
+
+    const machine = await ctx.db.get(tokenRecord.machineId)
+    if (!machine || machine.status === "REVOKED") {
+      return { valid: false }
+    }
+
+    return { valid: true, tenantId: tokenRecord.tenantId }
+  },
+})
+
+// Action para gerar URL de upload (validada por token de maquina)
+export const generateMachineUploadUrl = action({
+  args: {
+    machineToken: v.string(),
+    fileName: v.string(),
+    fileType: v.string(),
+    fileSize: v.number(),
+  },
+  handler: async (ctx, args) => {
+    // Validar token
+    const validation = await ctx.runQuery(api.liveChat.validateMachineTokenForUpload, {
+      machineToken: args.machineToken,
+    })
+
+    if (!validation.valid) {
+      throw new ConvexError("Token de máquina inválido")
+    }
+
+    // Validar tipo de arquivo
+    const ext = args.fileName.toLowerCase().slice(args.fileName.lastIndexOf("."))
+    if (!ALLOWED_EXTENSIONS.includes(ext)) {
+      throw new ConvexError(`Tipo de arquivo não permitido. Permitidos: ${ALLOWED_EXTENSIONS.join(", ")}`)
+    }
+
+    if (!ALLOWED_MIME_TYPES.includes(args.fileType)) {
+      throw new ConvexError("Tipo MIME não permitido")
+    }
+
+    // Validar tamanho
+    if (args.fileSize > MAX_FILE_SIZE) {
+      throw new ConvexError(`Arquivo muito grande. Máximo: ${MAX_FILE_SIZE / 1024 / 1024}MB`)
+    }
+
+    // Gerar URL de upload
+    const uploadUrl = await ctx.storage.generateUploadUrl()
+
+    return { uploadUrl }
+  },
+})