[ColinLeeo]

Java writes BOOLEAN columns with RLE by default, but the C++ decoder factory rejects BOOLEAN + RLE even though Int32RleDecoder::read_boolean() already exists. Reading these files therefore fails when the reader allocates the value decoder.

This change routes BOOLEAN + RLE to the existing decoder and adds a factory regression test. The existing cross-language compatibility workflow now generates 12 additional Java fixtures using a schema with no explicit encoding, asserts that the Java default is RLE, and validates the on-wire encoding and every value in C++. The fixtures cover UNCOMPRESSED/LZ4/ZSTD/LZMA2, alternating bits, long true/false runs, mixed NULL pages, and all-NULL pages.

Validation:

• Reproduced the factory and Java-to-C++ fixture failures before the fix.
• Java fixture generation and readback passed.
• C++ readback of all 135 Java fixtures passed, including the 12 new BOOLEAN fixtures.
• Encoding regression selection: 29 tests passed.
• Additional RLE/reader regression selection: 48 tests passed (one existing disabled test).
• Java and C++ Spotless checks and git diff --check passed.