refactor(core): drop redundant section banners from BitpackedEncoding

Inner class names are self-documenting.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: dfa1

CLAUDE.md

@@ -143,13 +143,8 @@ public final class FooEncoding implements Encoding {
     @Override public EncodeResult encode(DType dtype, Object data) { return Encoder.encode(dtype, data); }
     @Override public Array decode(DecodeContext ctx) { return Decoder.decode(ctx); }
 
-    private static final class Encoder {
-        static EncodeResult encode(DType dtype, Object data) { ... }
-    }
-
-    private static final class Decoder {
-        static Array decode(DecodeContext ctx) { ... }
-    }
+    private static final class Encoder { static EncodeResult encode(DType dtype, Object data) { ... } }
+    private static final class Decoder { static Array decode(DecodeContext ctx) { ... } }
 }
 ```
 

core/src/main/java/io/github/dfa1/vortex/encoding/BitpackedEncoding.java

@@ -59,8 +59,6 @@ public Array decode(DecodeContext ctx) {
 		return Decoder.decode(ctx);
 	}
 
-	// ── Encoder ───────────────────────────────────────────────────────────────
-
 	private static final class Encoder {
 
 		static EncodeResult encode(DType dtype, Object data) {
@@ -249,8 +247,6 @@ private static void writeWordToSeg(MemorySegment seg, int off, long value, int t
 		}
 	}
 
-	// ── Decoder ───────────────────────────────────────────────────────────────
-
 	private static final class Decoder {
 
 		static Array decode(DecodeContext ctx) {