fix: add timeout to opencode connection testing

[dimavedenyapin]

Summary

The OpenCode server (TypeScript, not Go) lazily initializes InstanceState (providers, models, auth) on the first request that touches instance routes — not at server startup. The SDK's createOpencode resolves as soon as the server prints "listening", before providers are loaded.

Our adapter called config.update() (with noTimeoutFetch = infinite timeout) in three places, each triggering this lazy init:

1. ensureServerRunning — config push with auth.json keys
2. createSession — plugin registration
3. resumeSession — plugin registration

The lazy init involves network calls (models.dev/api.json, plugin auth loaders for custom providers like routerai.ru, api.featherless.ai) that can block for minutes on slow networks. With infinite timeout on all SDK calls, both the Settings → Agents "Testing connection..." and the transcript session startup would hang indefinitely.

Changes

• Add quickClient with 15s timeout for health checks, provider listing, and config queries
• Make all 3 config.update() calls fire-and-forget — they trigger the expensive lazy init but don't need to block session startup or connection testing
• UI: treat null provider result as "connected" — health check already passed, provider counts show 0 until server finishes loading

Root cause confirmed from source

• OpenCode server lazy init — InstanceState.make() with ModelsDev.get() and plugin loaders
• ModelsDev.get() — fetches models.dev/api.json (10s timeout), plugin auth loaders (no timeout)
• Provider route handler — blocks HTTP response until InstanceState init completes

Test plan

• Settings → Agents: "Testing connection..." resolves within ~15s (shows "Connected" even if providers still loading)
• Start a new task with OpenCode agent: transcript appears quickly without minutes of empty spinner
• Resume an existing session: loads without minutes of delay
• Agent prompts still work correctly (they use the separate sharedClient with no timeout)
• Secret injection plugin still works after fire-and-forget registration

🤖 Generated with Claude Code