Support disabling well-known remote config entries and graceful fetch failure #23116

Summary

When a .well-known/opencode remote config URL is unreachable (e.g. VPN off, offline, GitHub Pages down), OpenCode crashes on startup with:

{
  "name": "UnknownError",
  "data": {
    "message": "Error: Unable to connect. Is the computer able to access the url?"
  }
}

There is no way to temporarily disable a well-known entry or recover without manually editing ~/.local/share/opencode/auth.json.

Problem

1. No disable mechanism — The WellKnown schema only has type, key, token. Adding "enabled": false to auth.json is silently ignored.
2. Hard failure on unreachable URL — The fetch in config/config.ts throws on failure with no try/catch, blocking all of OpenCode from starting.
3. No env var or CLI flag to skip remote config fetching (there is OPENCODE_DISABLE_PROJECT_CONFIG but nothing equivalent for remote/well-known).

Proposed Solution

1. Respect an enabled field on well-known auth entries

Add an optional enabled field to the WellKnown schema (default true). When false, skip fetching.

export class WellKnown extends Schema.Class<WellKnown>("WellKnownAuth")({
  type: Schema.Literal("wellknown"),
  key: Schema.String,
  token: Schema.String,
  enabled: Schema.optionalWith(Schema.Boolean, { default: () => true }),
}) {}

2. Graceful fetch failure

Wrap the well-known fetch in a try/catch. On failure, log a warning and continue startup without the remote config rather than crashing.

3. (Optional) Add OPENCODE_DISABLE_REMOTE_CONFIG env var

Similar to OPENCODE_DISABLE_PROJECT_CONFIG, allow skipping all remote config fetches via an environment variable.

Relevant Source

• packages/opencode/src/auth/index.ts — WellKnown schema
• packages/opencode/src/config/config.ts — loadInstanceState function, wellknown fetch loop