security: Bridge代理fetch+移除跨域设置+CSP头限制

CRITICAL修复:
- 移除allowFileAccessFromFileURLs/allowUniversalAccessFromFileURLs
- 移除mixedContentMode=ALWAYS_ALLOW
- WebViewClient注入CSP: default-src 'none';script-src 'unsafe-inline';connect-src 'none'
- 新增Bridge.fetchManifest(channel)/Bridge.fetchText(path)原生HTTP代理
- manifest JSON + version.txt通过Bridge读取,无需WebView跨域

packages/client-android/android/app/src/main/java/dev/yuzu/gca/MainActivity.kt

@@ -3,8 +3,11 @@ package dev.yuzu.gca
 import android.os.Bundle
 import android.util.Log
 import android.webkit.WebView
+import android.webkit.WebViewClient
 import androidx.appcompat.app.AppCompatActivity
 import java.io.File
+import java.net.HttpURLConnection
+import java.net.URL
 
 class MainActivity : AppCompatActivity() {
 
@@ -20,10 +23,17 @@ class MainActivity : AppCompatActivity() {
             settings.javaScriptEnabled = true
             settings.domStorageEnabled = true
             settings.allowFileAccess = true
-            settings.allowFileAccessFromFileURLs = true
-            settings.allowUniversalAccessFromFileURLs = true
-            settings.mixedContentMode = android.webkit.WebSettings.MIXED_CONTENT_ALWAYS_ALLOW
             addJavascriptInterface(Bridge(this@MainActivity), "Android")
+            webViewClient = object : WebViewClient() {
+                override fun onPageFinished(view: WebView, url: String) {
+                    view.evaluateJavascript("""
+                        var meta = document.createElement('meta');
+                        meta.httpEquiv = 'Content-Security-Policy';
+                        meta.content = "default-src 'none'; script-src 'unsafe-inline'; connect-src 'none'";
+                        document.head.appendChild(meta);
+                    """.trimIndent(), null)
+                }
+            }
 
             if (cacheFile.exists()) {
                 val html = cacheFile.readText()
@@ -47,17 +57,57 @@ class MainActivity : AppCompatActivity() {
             ctx.cacheFile.writeText(html)
             Log.i(TAG, "Hot-update HTML saved (${html.length}B)")
         }
+
         @android.webkit.JavascriptInterface
         fun clearCache() {
             ctx.cacheFile.delete()
             Log.i(TAG, "Cache cleared")
         }
+
         @android.webkit.JavascriptInterface
         fun sha256(input: String): String {
             val md = java.security.MessageDigest.getInstance("SHA-256")
             val digest = md.digest(input.toByteArray(Charsets.UTF_8))
             return digest.joinToString("") { "%02x".format(it) }
         }
+
+        /** Fetch manifest JSON from Gitea — proxy to avoid CORS in WebView */
+        @android.webkit.JavascriptInterface
+        fun fetchManifest(channel: String): String {
+            val url = "https://git.childish-ghost.com/LukeMackin/Yuzu-GCA/raw/branch/main/ota/h5/manifest-$channel.json"
+            Log.i(TAG, "Bridge fetching $url")
+            return try {
+                val conn = URL(url).openConnection() as HttpURLConnection
+                conn.connectTimeout = 10_000
+                conn.readTimeout = 10_000
+                conn.instanceFollowRedirects = true
+                val code = conn.responseCode
+                if (code != 200) throw Exception("HTTP $code")
+                conn.inputStream.bufferedReader().readText()
+            } catch (e: Exception) {
+                Log.e(TAG, "Bridge fetch failed: ${e.message}")
+                """{"error":"${e.message}"}"""
+            }
+        }
+
+        /** Fetch text file from Gitea — proxy for version.txt etc */
+        @android.webkit.JavascriptInterface
+        fun fetchText(path: String): String {
+            val url = "https://git.childish-ghost.com/LukeMackin/Yuzu-GCA/raw/branch/main/ota/$path"
+            Log.i(TAG, "Bridge fetching $url")
+            return try {
+                val conn = URL(url).openConnection() as HttpURLConnection
+                conn.connectTimeout = 10_000
+                conn.readTimeout = 10_000
+                conn.instanceFollowRedirects = true
+                val code = conn.responseCode
+                if (code != 200) throw Exception("HTTP $code")
+                conn.inputStream.bufferedReader().readText()
+            } catch (e: Exception) {
+                Log.e(TAG, "Bridge fetchText($path) failed: ${e.message}")
+                "ERROR: ${e.message}"
+            }
+        }
     }
 
     companion object { private const val TAG = "GCA-H5" }