v2.1.70: ~30s startup delay before typing is responsive (WSL2)

Environment

• Claude Code v2.1.70 (native install, Linux x86_64)
• WSL2 Ubuntu on Windows (kernel 6.6.87.2-microsoft-standard-WSL2)
• 0 MCP servers enabled
• 1 plugin enabled (example-skills from anthropic-agent-skills marketplace)
• Custom statusline command (runs in 0.01s)

Problem

After launching claude, it takes approximately 25-30 seconds before typed characters appear reliably in the input. During this period:

• Characters appear with significant delay (multiple seconds)
• The UI is rendered but input is laggy/blocked
• After ~30s it "catches up" and becomes responsive

What I've ruled out

| Component | Time | Status |
|---|---|---|
| Shell init (.bashrc) | 0.017s | Optimized (lazy NVM + conda) |
| MCP servers | 0s | All disabled |
| Statusline command | 0.01s | Fast |
| Claude binary load | 0.23s | Fast |
| Network (api.anthropic.com) | 0.11s | Fine |
| Network (statsig.anthropic.com) | 0.17s | Fine |
| DNS resolution | 0.09-0.15s | Fine |

The ~25s unaccounted time appears to be internal to Claude Code's startup — likely plugin marketplace git fetch, skills parsing, feature flag evaluation, or TUI initialization blocking the input loop.

Observed suspects

• Plugin marketplace: ~/.claude/plugins/marketplaces/claude-plugins-official/ (22MB git repo, does git fetch on startup ~0.8s)
• ~/.claude.json has 102 cached feature flags and 22 project entries (59KB file)
• Statsig cache is from January (stale?)

Expected behavior

Input should be responsive within 1-2 seconds of launch.

Reproduction

1. Install Claude Code v2.1.70 natively on WSL2 Ubuntu
2. Have a plugin marketplace configured
3. Launch claude
4. Try typing immediately — characters are severely delayed for ~30s