docs: changelog entry for #209

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: dfa1

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - CSV export renders unsigned integer columns (U8–U64) with their unsigned values — high-half values previously printed as two's-complement negatives (uci-wine `magnesium` U8 132 exported as -124), silent corruption found by the Raincloud conformance suite. ([#208](https://github.com/dfa1/vortex-java/issues/208))
+- `fastlanes.rle` decodes F64/F32 value pools (`LazyRleDoubleArray`, `LazyRleFloatArray`) — files from the Python bindings RLE-encode double columns with long constant runs, which previously failed to scan with `unsupported ptype F64`. ([#209](https://github.com/dfa1/vortex-java/issues/209))
 
 ## [0.12.0] — 2026-07-04