fix(opencode): recover malformed GLM/NVIDIA tool calls

[ctharvey]

Issue for this PR

Closes #25970

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

This hardens the @ai-sdk/openai-compatible path against malformed tool-call payloads seen from nvidia/z-ai/glm-5.1.

It does three things:

• supports legacy function_call responses alongside tool_calls
• tolerates streamed tool calls that are missing id or receive function.name later
• if a stream ends with finish_reason: "tool_calls" but no usable tool name, performs one non-stream recovery request and then raises a clear error instead of hanging

This keeps the provider bug from turning into a stalled OpenCode session.

How did you verify your code works?

• bun typecheck from packages/opencode
• bun test test/provider/copilot/openai-compatible-tool-call-id-fallback.test.ts --timeout 30000 from packages/opencode
• bun run build -- --single --skip-embed-web-ui from packages/opencode
• Reproduced with dist/opencode-windows-x64/bin/opencode.exe run --format json --dangerously-skip-permissions -m nvidia/z-ai/glm-5.1 "check your memory" on build 0.0.0-dev-202605060426

Notes:

• repo-root bun typecheck currently fails in unrelated existing packages/enterprise/src/custom-elements.d.ts
• the full packages/opencode suite also has existing Windows failures in unrelated PTY/symlink/filesystem tests, but the touched provider test passes

Screenshots / recordings

Not a UI change.

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR