feat: add TRANSPORT_ENCRYPTION toggle for easier deployment

- Add TRANSPORT_ENCRYPTION env config (default: false)
- Allow HTTP/IP access when transport encryption is disabled
- Add /api/crypto/config endpoint to expose encryption status
- Update WebCryptoEnvironmentCheck with 'disabled' status
- Update ExchangeConfigModal and AITradersPage to allow form submission when disabled
- Add i18n translations for disabled status (EN/CN)
- Update README with two deployment modes documentation

web/src/lib/crypto.ts

@@ -7,6 +7,10 @@ export interface EncryptedPayload {
   ts?: number // 可选：unix 秒，用于重放保护
 }
 
+export interface CryptoConfig {
+  transport_encryption: boolean
+}
+
 export interface WebCryptoEnvironmentInfo {
   isBrowser: boolean
   isSecureContext: boolean
@@ -20,6 +24,11 @@ export interface WebCryptoEnvironmentInfo {
 export class CryptoService {
   private static publicKey: CryptoKey | null = null
   private static publicKeyPEM: string | null = null
+  private static _transportEncryption: boolean | null = null
+
+  static get transportEncryption(): boolean {
+    return this._transportEncryption === true
+  }
 
   static async initialize(publicKeyPEM: string) {
     if (this.publicKey && this.publicKeyPEM === publicKeyPEM) {
@@ -29,6 +38,16 @@ export class CryptoService {
     this.publicKey = await this.importPublicKey(publicKeyPEM)
   }
 
+  static async fetchCryptoConfig(): Promise<CryptoConfig> {
+    const response = await fetch('/api/crypto/config')
+    if (!response.ok) {
+      throw new Error(`Failed to fetch crypto config: ${response.statusText}`)
+    }
+    const data = await response.json()
+    this._transportEncryption = data.transport_encryption
+    return data
+  }
+
   private static async importPublicKey(pem: string): Promise<CryptoKey> {
     const pemHeader = '-----BEGIN PUBLIC KEY-----'
     const pemFooter = '-----END PUBLIC KEY-----'
@@ -153,7 +172,11 @@ export class CryptoService {
       throw new Error(`Failed to fetch public key: ${response.statusText}`)
     }
     const data = await response.json()
-    return data.public_key
+    // Update transport encryption flag from server response
+    if (typeof data.transport_encryption === 'boolean') {
+      this._transportEncryption = data.transport_encryption
+    }
+    return data.public_key || ''
   }
 
   static async decryptSensitiveData(