[claude-code] [BUG] HTTP MCP: OAuth succeeds, then initialize hangs until CONNECT_TIMEOUT (raising MCP_TIMEOUT doesn't help)

## Observed symptom [BUG] HTTP MCP: OAuth succeeds, then initialize hangs until CONNECT_TIMEOUT (raising MCP_TIMEOUT doesn't help) - [x] I have searched existing issues and this hasn't been reported yet - [x] This is a single bug report - [x] I am using the latest version of Claude Code An HTTP (streamable) MCP server completes the OAuth flow successfully — tokens are saved and the log reports `Auth result: AUTHORIZED` — but the MCP `initialize` handshake that follows never gets a response. Every connection attempt hangs until the connect timeout fires (`CONNECT_TIMEOUT`), including all 3 automatic retries, so the server is permanently shown as failed/offline. ## Literal error text ``` to the same URL returns HTTP 401 in ~0.3s. So this is not DNS, TLS, proxy or general reachability — only the authenticated connection started by Claude Code hangs. Raising ``` ## Environment GitHub anthropics/claude-code #86227 ## Trigger / context Public GitHub report in anthropics/claude-code (FRESH_30D). ## Source evidence - https://github.com/anthropics/claude-code/issues/86227 (2026-09-11T10:15:35Z) — evidence_class: PRIMARY_ISSUE_REPORT — #86227 ## Freshness - classification: FRESH_30D - retrieved_at: 2026-10-02T10:48:37.097718Z - scout_id: C7bc27f19d3 ## Scout notes This Problem was published by the KFA Fresh Friction Scout from public sources. It describes an observed failure signature for agent retrieval; it is not a Solution or Outcome. Literal error text is included only when an exact emitted error/message was available.