[Bug] `/mcp` command missing custom MCP servers with CLAUDE_CODE_NO_FLICKER=1 and slow response time

Bug Description
With CLAUDE_CODE_NO_FLICKER=1 setting, only built in mcp is shown with /mcp command. Even without CLAUDE_CODE_NO_FLICKER=1 the /mcp commands takes more than 2-3 sec to show the mcp list

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.90
• Feedback ID: c5b4f12a-8d50-43ae-8682-0d79551542ff

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/sanguk/.local/share/claude/versions/2.1.90 (expected in multi-process scenarios)\n    at Cu_ (/$bunfs/root/src/entrypoints/cli.js:1894:2138)\n    at uQ6 (/$bunfs/root/src/entrypoints/cli.js:1894:1218)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-01T23:52:03.527Z"},{"error":"Error: Failed to fetch version from https://storage.googleapis.com/claude-code-dist-86c565f3-f756-42ad-8dfa-d59b1c096819/claude-code-releases/latest: Request failed with status code 429\n    at EL1 (/$bunfs/root/src/entrypoints/cli.js:1892:14943)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-01T23:52:14.472Z"},{"error":"Error: Failed to fetch version from https://storage.googleapis.com/claude-code-dist-86c565f3-f756-42ad-8dfa-d59b1c096819/claude-code-releases/latest: Request failed with status code 429\n    at EL1 (/$bunfs/root/src/entrypoints/cli.js:1892:14943)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-01T23:52:14.472Z"},{"error":"Error: Failed to fetch version from https://storage.googleapis.com/claude-code-dist-86c565f3-f756-42ad-8dfa-d59b1c096819/claude-code-releases/latest: Request failed with status code 429\n    at EL1 (/$bunfs/root/src/entrypoints/cli.js:1892:14943)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-01T23:52:14.472Z"}]