Add remote MCP capture transport

[askmy-stack]

Summary

Add remote MCP capture support beyond the existing local stdio transport.

Scope

Decide and document supported MCP remote transport(s), then capture tools, prompts, and resources into the existing deterministic InterfaceSnapshot format.

Acceptance criteria

• Supported remote transport(s) and authentication boundaries are documented
• CLI accepts a remote endpoint without treating metadata as trusted
• Capture output is deterministic across repeated runs
• Secret-like metadata is redacted
• Tests cover success, invalid endpoint, and authentication/error paths
• Existing stdio capture behavior remains unchanged