External MCP Servers previously only spoke stdio (spawn a local
command + args). Adds:
- env vars for stdio servers (merged into the subprocess environment,
not embedded in the args string), with a masked key-value editor
- a native Streamable HTTP transport (URL + Bearer token + custom
headers), so HTTP-based MCP servers like Obsidian's Local REST API
plugin connect directly without needing npx/Node.js as a bridge
Introduces an MCPTransport abstraction (stdio/HTTP) so ExternalMCPClient
stays transport-agnostic — mirrors how Provider.swift already abstracts
AI backends in this codebase.
Also fixes a real crash found via live testing against Obsidian:
convertInputSchema force-unwrapped a tool parameter's `type`, which
isn't required by JSON Schema — Obsidian's plugin was the first real
server to send a parameter without one. Live-verified end to end
(vault search/read/write/edit) before this commit, per the project's
standing rule to hold external-service-dependent changes until they're
actually confirmed working, not just compiling and passing tests.
rune
25028e3405