fix: request assistant reply for structured output

[huilang021x]

Summary

• What changed: Use noReply: false for transient OpenCode structured-output prompts and update the opencode-provider regression test.
• Why: OpenCode treats noReply: true as context-only, returning before the assistant loop that populates info.structured.
• Current phase: Ready for review.

Scope

• In scope: generateStructuredOutput() calls through OpenCode v2 session.prompt; related unit test expectation.
• Out of scope: External provider implementations, auto-capture retry behavior, embedding/search behavior.
• Risk level: Low; the structured request already uses a transient session that is deleted afterward.

Deployment Targets

• Impacted services: OpenCode plugin runtime only.
• Restart/deploy needed: Users need to restart OpenCode after updating the plugin.
• Target environment: Any environment using opencodeProvider + opencodeModel for auto-capture/profile structured output.
• Rollback note: Revert this commit to restore the previous noReply: true request behavior.

Acceptance Plan

• Acceptance criteria: Structured-output prompts enter the assistant loop and return info.structured; transient sessions are still deleted.
• Evidence to collect: Unit and full test suite results.
• Required checks: Repository CI, if configured.
• Manual verification needed: Optional, against a live OpenCode server/provider.

Validation

• Commands run:
  • bun test tests/opencode-provider.test.ts
  • bun run typecheck
  • bun run format:check
  • bun run build && bun test
• Result: Passed.
• Evidence links/log snippets: Final full test run: 156 pass, 0 fail.

[huilang021x]

@codex please review this PR when you have a chance.

Context: this fixes OpenCode structured output usage by requesting an assistant reply instead of noReply: true, which currently produces no info.structured.

[huilang021x]

@codex review 5961ae1