feat: mcp-server credential fallback, chat reuse docs

[jflayhart]

Regenerated by stlc. This release carries one hand-written change and one spec change.

1. mcp-server falls back to the linq CLI credential

packages/mcp-server/src/linq-cli-credentials.ts (new), wired in index.ts.

MCP clients launch the server as a detached child process, so it never inherits a login shell. On macOS a GUI-launched editor does not see export LINQ_API_V3_API_KEY=... from a shell profile — which leaves the env var, the only supported credential source, unreachable for most desktop users.

The server now reads the token linq login already wrote to ~/.linq/config.json when the env var is unset, honouring LINQ_PROFILE and the config's active profile. An explicitly provided key still wins. Every failure path — file absent, unreadable, malformed, or tokenless — falls through to the previous behaviour, so the SDK still reports the missing credential itself.

This was driven by a concrete finding: a relative script path in a Cursor plugin's mcp.json does not resolve to the plugin root (Cursor looks in the open workspace; the spawned process cwd is $HOME), so a launcher script could not be used to supply the key. Resolving it in the server removes the need for one, and Claude Code and Codex get the same fix.

Verified end to end with no env var set: the server logged Using the API key from ~/.linq/config.json, the Deno sandbox booted, and an authenticated phone_numbers call returned live data.

This is sealed as custom code

The patch lives in linq-sdks at stainless/custom-code/typescript/, so a future regeneration re-applies it instead of reverting it. That matters here specifically: f8bdf2d fixed the Deno sandbox by hand, 567485d1 regenerated over it, and 0.29.0 shipped with execute broken on every call. The same tracking file also carries that --allow-net fix, already released in 0.30.0.

Please do not hand-edit packages/mcp-server/src/linq-cli-credentials.ts or the --allow-net flag in code-tool.ts on main — edits there are erased by the next regeneration. Change them via stlc build --commit in linq-sdks.

2. Document chat reuse and named-group behaviour

src/resources/chats/chats.ts and the mcp-server docs index, regenerated from the OpenAPI spec change in synapse. Documentation only; no behaviour change.

Checks

lint and build pass. Merging cuts 0.31.0 via release-please.