refactor(skill-mcp-manager): split manager.ts into connection and client modules

Extract MCP client lifecycle management:
- connection.ts: getOrCreateClientWithRetry logic
- stdio-client.ts, http-client.ts: transport-specific creation
- oauth-handler.ts: OAuth token management
- cleanup.ts: session and global cleanup
- connection-type.ts: connection type detection

src/features/skill-mcp-manager/oauth-handler.ts

@@ -0,0 +1,100 @@
+import type { ClaudeCodeMcpServer } from "../claude-code-mcp-loader/types"
+import { McpOAuthProvider } from "../mcp-oauth/provider"
+import type { OAuthTokenData } from "../mcp-oauth/storage"
+import { isStepUpRequired, mergeScopes } from "../mcp-oauth/step-up"
+
+export function getOrCreateAuthProvider(
+  authProviders: Map<string, McpOAuthProvider>,
+  serverUrl: string,
+  oauth: NonNullable<ClaudeCodeMcpServer["oauth"]>
+): McpOAuthProvider {
+  const existing = authProviders.get(serverUrl)
+  if (existing) return existing
+
+  const provider = new McpOAuthProvider({
+    serverUrl,
+    clientId: oauth.clientId,
+    scopes: oauth.scopes,
+  })
+  authProviders.set(serverUrl, provider)
+  return provider
+}
+
+function isTokenExpired(tokenData: OAuthTokenData): boolean {
+  if (tokenData.expiresAt == null) return false
+  return tokenData.expiresAt < Math.floor(Date.now() / 1000)
+}
+
+export async function buildHttpRequestInit(
+  config: ClaudeCodeMcpServer,
+  authProviders: Map<string, McpOAuthProvider>
+): Promise<RequestInit | undefined> {
+  const headers: Record<string, string> = {}
+
+  if (config.headers) {
+    for (const [key, value] of Object.entries(config.headers)) {
+      headers[key] = value
+    }
+  }
+
+  if (config.oauth && config.url) {
+    const provider = getOrCreateAuthProvider(authProviders, config.url, config.oauth)
+    let tokenData = provider.tokens()
+
+    if (!tokenData || isTokenExpired(tokenData)) {
+      try {
+        tokenData = await provider.login()
+      } catch {
+        tokenData = null
+      }
+    }
+
+    if (tokenData) {
+      headers.Authorization = `Bearer ${tokenData.accessToken}`
+    }
+  }
+
+  return Object.keys(headers).length > 0 ? { headers } : undefined
+}
+
+export async function handleStepUpIfNeeded(params: {
+  error: Error
+  config: ClaudeCodeMcpServer
+  authProviders: Map<string, McpOAuthProvider>
+}): Promise<boolean> {
+  const { error, config, authProviders } = params
+
+  if (!config.oauth || !config.url) {
+    return false
+  }
+
+  const statusMatch = /\b403\b/.exec(error.message)
+  if (!statusMatch) {
+    return false
+  }
+
+  const headers: Record<string, string> = {}
+  const wwwAuthMatch = /WWW-Authenticate:\s*(.+)/i.exec(error.message)
+  if (wwwAuthMatch?.[1]) {
+    headers["www-authenticate"] = wwwAuthMatch[1]
+  }
+
+  const stepUp = isStepUpRequired(403, headers)
+  if (!stepUp) {
+    return false
+  }
+
+  const currentScopes = config.oauth.scopes ?? []
+  const mergedScopes = mergeScopes(currentScopes, stepUp.requiredScopes)
+  config.oauth.scopes = mergedScopes
+
+  authProviders.delete(config.url)
+  const provider = getOrCreateAuthProvider(authProviders, config.url, config.oauth)
+
+  try {
+    await provider.login()
+    return true
+  } catch {
+    return false
+  }
+}