## Summary
Stabilizes the Go unit-test surface so the test suite can run reliably
in CI and locally via \`bash build.sh --test\`.
## Verification
\`\`\`bash
bash build.sh --test -- -count=10 -run TestWithCancel_SequentialAgent
./internal/harness/core/
bash build.sh --test -- -count=5 -run TestSiliconflowChatExtracts
./internal/entity/models/
bash build.sh --test # full suite
\`\`\`
All previously failing packages (\`admin\`, \`cli\`, \`handler\`,
\`parser\`,
\`router\`, \`service\`, \`service/chunk\`) now build and test
successfully.
\`TestWithCancel_SequentialAgent\` passes 10/10 (was flaky). SiliconFlow
reasoning test passes after switching the assertion to the SiliconFlow
wire
format.
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Co-authored-by: Claude <noreply@anthropic.com>