security(mcp): warn on sensitive field names in elicitation requests #2523
Description
Context
Added in #2521. MCP servers can send elicitation requests with field names like password, token, secret, api_key. Currently the agent prompts for these without any warning, creating a phishing vector.
Required work
- Detect field names matching a configurable list of sensitive patterns (password, token, secret, key, credential, etc.)
- Show a visible warning before prompting: "Warning: [server-name] is requesting sensitive information (field: password). Only proceed if you trust this server."
- Config:
[mcp] elicitation_warn_sensitive_fields = true(default true)