fix(auto-capture): reuse injected opencode client

[huilang021x]

Summary

• What changed: Auto-capture now builds its structured-output session client from the injected OpenCode ctx.client instead of creating a second client from ctx.serverUrl. session.create failures now include underlying status/error details when available.
• Why: In no-port OpenCode sessions, ctx.serverUrl can be http://localhost:4096/ even when no REST API is listening there, causing session.create returned no session id during auto-capture.
• Current phase: Ready for review. Closes Auto-capture uses unreachable ctx.serverUrl in no-port OpenCode sessions #145.

Scope

• In scope: Structured-output auto-capture client initialization and regression coverage for the injected-client adapter.
• Out of scope: Provider/model timeout tuning, storage/indexing behavior, web UI behavior.
• Risk level: Low/medium; changes the internal client used for auto-capture session create/prompt/delete while preserving the existing request shapes.

Deployment Targets

• Impacted services: opencode-mem plugin auto-capture and user-profile structured-output paths that use the shared opencode provider client.
• Restart/deploy needed: Users need to restart OpenCode after upgrading the plugin.
• Target environment: OpenCode plugin runtime.
• Rollback note: Revert this commit to restore the previous ctx.serverUrl client path.

Acceptance Plan

• Acceptance criteria: Auto-capture should not fail with no session id solely because ctx.serverUrl points to an unreachable default port; structured-output calls should use the injected client and still pass format, system, model, and parts correctly.
• Evidence to collect: Regression test verifies createStructuredOutputClient() maps v2-style calls onto the injected client without opening a new serverUrl client.
• Required checks: Typecheck, build, formatter check, targeted provider tests, full test suite.
• Manual verification needed: Optional validation in a no-port OpenCode runtime after publishing.

Validation

• Commands run:
  • bun test tests/opencode-provider.test.ts
  • bun run format:check
  • bun run typecheck
  • bun run build
  • bun test
• Result: All passed after formatting.
• Evidence links/log snippets:
  • Targeted test: 12 pass, 0 fail
  • Full test suite: 157 pass, 0 fail

[tickernelz]

I tried to merge this PR into the latest main as part of a batch release, but it currently has merge conflicts in:

• src/services/ai/opencode-provider.ts

Several structured-output / opencode-provider changes landed in the latest release, which is what this now collides with. Please rebase/merge the latest main and resolve the conflicts, and I'll merge it afterward.

[prihuda]

i need this because on 2.18.0 the problem still persist

[GraDea]

The goal is right: structured auto-capture should reuse OpenCode’s running host context instead of depending on a separately reachable localhost server.

I’m going to hold/close this in favor of #161, because this PR routes back through ctx.client.session.create/prompt/delete, while #140 intentionally moved away from those SDK/session helper methods due SDK shape brittleness.

The replacement approach keeps #140’s raw endpoint direction, but uses the host SDK transport (fetch/baseUrl) underneath it. It also covers the follow-up issues we found in runtime testing:

• injected host fetch needs Request object calls
• noReply: true suppresses structured output in current OpenCode builds
• info.structured_output must be supported
• diagnostics need redaction
• stale host transport state must be reset between plugin initializations

Closing as superseded by #161, not rejected.