feat: 导出 SproutClaw .sproutclaw 配置

包含 extensions、skills、prompts、settings、auth、models、mcp 等配置。
排除 node_modules、npm 缓存、sessions 等运行时数据。

agent/extensions/pi-mcp-adapter/oauth-handler.ts

@@ -0,0 +1,57 @@
+// oauth-handler.ts - OAuth token management for MCP servers
+import { existsSync, readFileSync } from "node:fs";
+import type { OAuthTokens } from "@modelcontextprotocol/sdk/shared/auth.js";
+import { getAuthEntryFilePath } from "./mcp-auth.ts";
+
+// Token storage path for a server
+function getTokensPath(serverName: string): string {
+  return getAuthEntryFilePath(serverName);
+}
+
+/**
+ * Get stored OAuth tokens for a server (if any).
+ * Returns undefined if no tokens or tokens are expired.
+ * 
+ * Token file location: $MCP_OAUTH_DIR/sha256-<server-hash>/tokens.json when set,
+ * otherwise <Pi agent dir>/mcp-oauth/sha256-<server-hash>/tokens.json
+ * 
+ * Expected format:
+ * {
+ *   "access_token": "...",
+ *   "token_type": "bearer",
+ *   "refresh_token": "...",  // optional
+ *   "expires_in": 3600,      // optional, seconds
+ *   "expiresAt": 1234567890  // optional, absolute timestamp ms
+ * }
+ */
+export function getStoredTokens(serverName: string): OAuthTokens | undefined {
+  const tokensPath = getTokensPath(serverName);
+  
+  if (!existsSync(tokensPath)) return undefined;
+  
+  try {
+    const stored = JSON.parse(readFileSync(tokensPath, "utf-8"));
+    
+    // Validate required field
+    if (!stored.access_token || typeof stored.access_token !== "string") {
+      return undefined;
+    }
+    
+    // Check expiration if expiresAt is set
+    if (stored.expiresAt && typeof stored.expiresAt === "number") {
+      if (Date.now() > stored.expiresAt) {
+        // Token expired
+        return undefined;
+      }
+    }
+    
+    return {
+      access_token: stored.access_token,
+      token_type: stored.token_type ?? "bearer",
+      refresh_token: stored.refresh_token,
+      expires_in: stored.expires_in,
+    };
+  } catch {
+    return undefined;
+  }
+}