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>

apps/desktop/src-tauri/src/chat.rs

@@ -218,16 +218,21 @@ pub async fn send_message(
     token: &str,
     ticket_id: &str,
     body: &str,
+    attachments: Option<Vec<AttachmentPayload>>,
 ) -> Result<SendMessageResponse, String> {
     let url = format!("{}/api/machines/chat/messages", base_url);
 
-    let payload = serde_json::json!({
+    let mut payload = serde_json::json!({
         "machineToken": token,
         "ticketId": ticket_id,
         "action": "send",
         "body": body,
     });
 
+    if let Some(atts) = attachments {
+        payload["attachments"] = serde_json::to_value(atts).unwrap_or_default();
+    }
+
     let response = CHAT_CLIENT
         .post(&url)
         .json(&payload)
@@ -247,6 +252,150 @@ pub async fn send_message(
         .map_err(|e| format!("Falha ao parsear resposta de send: {e}"))
 }
 
+// ============================================================================
+// UPLOAD DE ARQUIVOS
+// ============================================================================
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct AttachmentPayload {
+    pub storage_id: String,
+    pub name: String,
+    pub size: Option<u64>,
+    #[serde(rename = "type")]
+    pub mime_type: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct UploadUrlResponse {
+    pub upload_url: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct UploadResult {
+    pub storage_id: String,
+}
+
+// Extensoes permitidas
+const ALLOWED_EXTENSIONS: &[&str] = &[
+    ".jpg", ".jpeg", ".png", ".gif", ".webp",
+    ".pdf", ".txt", ".doc", ".docx", ".xls", ".xlsx",
+];
+
+// Tamanho maximo: 10MB
+const MAX_FILE_SIZE: u64 = 10 * 1024 * 1024;
+
+pub fn is_allowed_file(file_name: &str, file_size: u64) -> Result<(), String> {
+    let ext = file_name
+        .to_lowercase()
+        .rsplit('.')
+        .next()
+        .map(|e| format!(".{}", e))
+        .unwrap_or_default();
+
+    if !ALLOWED_EXTENSIONS.contains(&ext.as_str()) {
+        return Err(format!(
+            "Tipo de arquivo não permitido. Permitidos: {}",
+            ALLOWED_EXTENSIONS.join(", ")
+        ));
+    }
+
+    if file_size > MAX_FILE_SIZE {
+        return Err(format!(
+            "Arquivo muito grande. Máximo: {}MB",
+            MAX_FILE_SIZE / 1024 / 1024
+        ));
+    }
+
+    Ok(())
+}
+
+pub fn get_mime_type(file_name: &str) -> String {
+    let lower = file_name.to_lowercase();
+    let ext = lower.rsplit('.').next().unwrap_or("");
+
+    match ext {
+        "jpg" | "jpeg" => "image/jpeg",
+        "png" => "image/png",
+        "gif" => "image/gif",
+        "webp" => "image/webp",
+        "pdf" => "application/pdf",
+        "txt" => "text/plain",
+        "doc" => "application/msword",
+        "docx" => "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+        "xls" => "application/vnd.ms-excel",
+        "xlsx" => "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+        _ => "application/octet-stream",
+    }
+    .to_string()
+}
+
+pub async fn generate_upload_url(
+    base_url: &str,
+    token: &str,
+    file_name: &str,
+    file_type: &str,
+    file_size: u64,
+) -> Result<String, String> {
+    let url = format!("{}/api/machines/chat/upload", base_url);
+
+    let payload = serde_json::json!({
+        "machineToken": token,
+        "fileName": file_name,
+        "fileType": file_type,
+        "fileSize": file_size,
+    });
+
+    let response = CHAT_CLIENT
+        .post(&url)
+        .json(&payload)
+        .send()
+        .await
+        .map_err(|e| format!("Falha na requisicao de upload URL: {e}"))?;
+
+    if !response.status().is_success() {
+        let status = response.status();
+        let body = response.text().await.unwrap_or_default();
+        return Err(format!("Upload URL falhou: status={}, body={}", status, body));
+    }
+
+    let data: UploadUrlResponse = response
+        .json()
+        .await
+        .map_err(|e| format!("Falha ao parsear resposta de upload URL: {e}"))?;
+
+    Ok(data.upload_url)
+}
+
+pub async fn upload_file(
+    upload_url: &str,
+    file_data: Vec<u8>,
+    content_type: &str,
+) -> Result<String, String> {
+    let response = CHAT_CLIENT
+        .post(upload_url)
+        .header("Content-Type", content_type)
+        .body(file_data)
+        .send()
+        .await
+        .map_err(|e| format!("Falha no upload: {e}"))?;
+
+    if !response.status().is_success() {
+        let status = response.status();
+        let body = response.text().await.unwrap_or_default();
+        return Err(format!("Upload falhou: status={}, body={}", status, body));
+    }
+
+    let data: UploadResult = response
+        .json()
+        .await
+        .map_err(|e| format!("Falha ao parsear resposta de upload: {e}"))?;
+
+    Ok(data.storage_id)
+}
+
 // ============================================================================
 // CHAT RUNTIME
 // ============================================================================
@@ -569,9 +718,9 @@ fn open_chat_window_internal(app: &tauri::AppHandle, ticket_id: &str) -> Result<
     .inner_size(380.0, 520.0)
     .min_inner_size(300.0, 400.0)
     .position(x, y)
-    .decorations(false) // Frameless
+    .decorations(true) // Usar decoracoes nativas do Windows
     .always_on_top(true)
-    .skip_taskbar(true)
+    .skip_taskbar(false) // Mostrar na taskbar
     .focused(true)
     .visible(true)
     .build()