fix: explicit & 0xff on byte | int bit-pack writes

SonarCloud S3034 flags 7 sites where a byte is OR'd with a positive int
mask, then cast back to byte. Behaviour was already correct (the cast
truncates the sign-extended upper bits), but the intermediate int result
is sign-extended and would be wrong if anyone read it before the cast.
Adding {@code & 0xff} on the byte side makes the unsigned-bit intent
explicit and quiet the rule.

Also drops the trivially-passing KeyTest#navigationKeysAreDistinct (S5845):
{@code isNotSameAs} between two distinct enum singletons is always true
at compile time. The PatternMatching test already covers distinctness
functionally.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: dfa1

cli/src/test/java/io/github/dfa1/vortex/cli/tui/term/KeyTest.java

@@ -40,16 +40,6 @@ void allArrowsAreSealedKeyVariants() {
             assertThat(Key.ArrowLeft.INSTANCE).isInstanceOf(Key.class);
             assertThat(Key.ArrowRight.INSTANCE).isInstanceOf(Key.class);
         }
-
-        @Test
-        void navigationKeysAreDistinct() {
-            // Given / When / Then — each singleton must be its own type;
-            // a switch in TUI code dispatches by identity-equivalent enum match.
-            assertThat(Key.PageUp.INSTANCE).isNotSameAs(Key.PageDown.INSTANCE);
-            assertThat(Key.Home.INSTANCE).isNotSameAs(Key.End.INSTANCE);
-            assertThat(Key.Enter.INSTANCE).isNotSameAs(Key.Escape.INSTANCE);
-            assertThat(Key.Eof.INSTANCE).isNotSameAs(Key.Escape.INSTANCE);
-        }
     }
 
     @Nested

inspector/src/main/java/io/github/dfa1/vortex/inspect/ZonedStatsSchema.java

@@ -110,7 +110,7 @@ public static List<Stat> presentStats(ByteBuffer metadata) {
         while (mb.hasRemaining()) {
             byte b = mb.get();
             for (int bit = 0; bit < 8; bit++) {
-                if ((b & (1 << bit)) != 0 && bitIndex < all.length) {
+                if (((b & 0xff) & (1 << bit)) != 0 && bitIndex < all.length) {
                     out.add(all[bitIndex]);
                 }
                 bitIndex++;

reader/src/main/java/io/github/dfa1/vortex/reader/array/MaterializedBoolArray.java

@@ -42,6 +42,6 @@ MemorySegment buffer() {
     @Override
     public boolean getBoolean(long i) {
         byte b = buffer.get(ValueLayout.JAVA_BYTE, i >>> 3);
-        return (b & (1 << (i & 7))) != 0;
+        return ((b & 0xff) & (1 << (i & 7))) != 0;
     }
 }

reader/src/main/java/io/github/dfa1/vortex/reader/decode/ByteBoolEncodingDecoder.java

@@ -36,7 +36,7 @@ public Array decode(DecodeContext ctx) {
             if (bytes.get(ValueLayout.JAVA_BYTE, i) != 0) {
                 long byteIdx = i >>> 3;
                 byte cur = packed.get(ValueLayout.JAVA_BYTE, byteIdx);
-                packed.set(ValueLayout.JAVA_BYTE, byteIdx, (byte) (cur | (1 << (i & 7))));
+                packed.set(ValueLayout.JAVA_BYTE, byteIdx, (byte) ((cur & 0xff) | (1 << (i & 7))));
             }
         }
         return new MaterializedBoolArray(ctx.dtype(), n, packed);

reader/src/main/java/io/github/dfa1/vortex/reader/decode/RleEncodingDecoder.java

@@ -131,7 +131,7 @@ public Array decode(DecodeContext ctx) {
             if (indicesValidity.getBoolean(offset + j)) {
                 int byteIdx = (int) (j >>> 3);
                 byte current = validityBuf.get(ValueLayout.JAVA_BYTE, byteIdx);
-                validityBuf.set(ValueLayout.JAVA_BYTE, byteIdx, (byte) (current | (1 << (j & 7))));
+                validityBuf.set(ValueLayout.JAVA_BYTE, byteIdx, (byte) ((current & 0xff) | (1 << (j & 7))));
             }
         }
         BoolArray outputValidity = new MaterializedBoolArray(new DType.Bool(false), rowCount, validityBuf);

reader/src/main/java/io/github/dfa1/vortex/reader/decode/RunEndEncodingDecoder.java

@@ -190,7 +190,7 @@ private static Array expandBool(
                 if (val) {
                     long byteIdx = outIdx >>> 3;
                     byte cur = out.get(ValueLayout.JAVA_BYTE, byteIdx);
-                    out.set(ValueLayout.JAVA_BYTE, byteIdx, (byte) (cur | (1 << (outIdx & 7))));
+                    out.set(ValueLayout.JAVA_BYTE, byteIdx, (byte) ((cur & 0xff) | (1 << (outIdx & 7))));
                 }
             }
             logicalPos = runEnd;

reader/src/main/java/io/github/dfa1/vortex/reader/decode/SparseEncodingDecoder.java

@@ -122,7 +122,7 @@ private static Array decodeBool(
                     long pos = readUnsignedIdx(idxSeg, SegmentBroadcast.elementOffset(idxSeg, i, idxBytes), indicesPtype) - offset;
                     long byteIdx = pos >>> 3;
                     byte cur = out.get(ValueLayout.JAVA_BYTE, byteIdx);
-                    out.set(ValueLayout.JAVA_BYTE, byteIdx, (byte) (cur | (1 << (pos & 7))));
+                    out.set(ValueLayout.JAVA_BYTE, byteIdx, (byte) ((cur & 0xff) | (1 << (pos & 7))));
                 }
             }
         }

writer/src/main/java/io/github/dfa1/vortex/writer/encode/BoolEncodingEncoder.java

@@ -27,7 +27,7 @@ private static MemorySegment encodeBool(boolean[] data, Arena arena) {
             if (data[i]) {
                 long byteIdx = i / 8;
                 byte cur = seg.get(ValueLayout.JAVA_BYTE, byteIdx);
-                seg.set(ValueLayout.JAVA_BYTE, byteIdx, (byte) (cur | (1 << (i % 8))));
+                seg.set(ValueLayout.JAVA_BYTE, byteIdx, (byte) ((cur & 0xff) | (1 << (i % 8))));
             }
         }
         return seg;