fix(tool): empty .opencode/tool/index.ts barrel to unblock opencode 1.14.49

[kunickiaj]

Summary

opencode 1.14.49 introduced a regression in ToolRegistry.state() that calls Object.entries() on the result of scanning each .opencode/tool/*.ts file. The current .opencode/tool/index.ts re-exports from ./gemini and ./env, which opencode tries to register as tools and crashes with:

TypeError: Object.entries requires that input parameter not be null or undefined
  at ToolRegistry.state
  at ToolRegistry.all
  at ToolRegistry.tools
  at SessionPrompt.resolveTools
  at SessionPrompt.run

For users this surfaces as Unexpected server error. Check server logs for details. on the very first prompt — opencode never even reaches the LLM call. opencode --print-logs run … is needed to see the underlying stack trace.

Why empty?

The barrel adds nothing functional:

• opencode auto-discovers tools per-subdirectory (.opencode/tool/gemini/, .opencode/tool/template/).
• Nothing in this repo imports from the barrel; tools are referenced via their subpaths.
• scripts/registry/validate-registry.ts already explicitly skips tool/index.ts.

I tried keeping only the actual tool re-exports (dropping just the env helpers) — opencode 1.14.49 still crashes. The scanner appears to fail on any re-export from tool/index.ts, not just non-tool ones. So the barrel has to be empty (or removed) to be safe on 1.14.49+.

opencode 1.14.48 silently tolerated the same barrel, which is why this hasn't surfaced before.

Repro

# install latest opencode
curl -fsSL https://opencode.ai/install | bash
opencode --version  # 1.14.49

# from any directory with this repo's .opencode/tool/index.ts in scope:
opencode --print-logs run "ping"
# → "Unexpected server error" with the trace above

User-side workaround until merged:

echo 'export {}' > .opencode/tool/index.ts

Test plan

• opencode 1.14.49 run ping fails with the existing tool/index.ts
• Same command succeeds after applying this patch
• Tool subdirectories (gemini, template) still auto-discovered and usable
• No other code imports the barrel (grep across .opencode/, scripts/, docs/)