test: minimal reproduction for inserting binary buffers into String/FixedString (#837)

[Copilot]

Summary

Adds a minimal reproduction test for #837: inserting raw binary Buffer data into a String/FixedString column via JSONEachRow. JSONEachRow values are interpreted as UTF-8 text, so any byte >= 0x80 is re-encoded into a multi-byte sequence — overflowing a FixedString (TOO_LARGE_STRING_SIZE) and silently corrupting a String.

Tests live in client-node only; the behavior is not yet exercised for the Web client.

• FixedString case — asserts insert fails with TOO_LARGE_STRING_SIZE (0xF0 → 0xC3 0xB0 overflows FixedString(2)).
• String case — asserts round-tripped bytes are corrupted (F0F0 → C3B0C3B0).
• Both cases added to packages/client-node/__tests__/integration/node_insert_binary_string.test.ts.

const binary = Buffer.from([0xf0, 0xf0]);
await client.insert({
  table, // fs FixedString(2)
  values: [{ fs: binary.toString("binary") }],
  format: "JSONEachRow",
}); // rejects: TOO_LARGE_STRING_SIZE

Checklist

• Unit and integration tests covering the common scenarios were added

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Codecov Report

✅ All modified and coverable lines are covered by tests.

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