Honor selected compression method for native TCP responses

[beejmaxx]

Problem

SetCompressionMethod(CompressionMethod::ZSTD) compresses blocks sent by the client with ZSTD, but the native Query packet carries only a boolean compression flag, not a codec name. The server chooses its response codec from network_compression_method, which this client does not send. A server configured for LZ4 can therefore return LZ4 blocks to a client configured for ZSTD. The client decodes them successfully, so the mismatch is silent.

Change

For LZ4 or ZSTD, send the corresponding network_compression_method with each query when the caller has not set it explicitly. Preserve the caller's setting and flags. Do not add a setting when compression is disabled or the server revision is too old for string-serialized settings.

Compatibility

This changes behavior for users whose server constrains network_compression_method. For example, a readonly user whose permitted server codec differs from the configured client codec can now receive a READONLY error for a query that previously succeeded with the server's codec. The client propagates the server error. The caller can choose a permitted codec, disable compression, or supply an explicit permitted per-query setting where the API allows one.

Verification

• Before the fix, regression tests failed for both mismatched cases: client ZSTD with server LZ4, and client LZ4 with server ZSTD.
• After the fix, 169 protocol, stream, client, and roundtrip tests passed on macOS arm64 with AppleClang 21 and ClickHouse 25.12.1.649; 2 existing tests were disabled.
• Captured server responses for both codecs and both explicit cross-codec overrides. Each case returned three checksum-validated frames using the expected codec, and the client decoded all 100 result rows.
• A scripted older server test inspects the emitted query bytes to verify that no automatic string setting is sent. A readonly integration test covers the rejection and a permitted explicit override.
• git diff --check passed. Bazel and Linux/Windows CI have not been run locally.

Fixes #556.

[CLAassistant]

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