Rename application identifier to space.rcmd.android.sizzle

Global rename of the app/package identifier from
com.reactorcoremeltdown.sizzletracker to space.rcmd.android.sizzle:

- build.gradle.kts: applicationId + namespace.
- Move the Kotlin source tree (main + test) and rewrite every package/import.
- native_audio.cpp: JNI symbol names (Java_space_rcmd_android_sizzle_...) so the
  Oboe callback still links against the relocated NativeAudioBridge.
- docs: package/file-map header.

The desktop-project GitHub URLs (github.com/reactorcoremeltdown/sizzletracker)
and the Reactorcoremeltdown copyright/SPDX author identity are intentionally left
unchanged. Note: the new applicationId installs as a separate package (existing
installs won't upgrade in place).

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

app/src/test/java/space/rcmd/android/sizzle/io/SngFormatTest.kt

@@ -0,0 +1,83 @@
+// SPDX-FileCopyrightText: 2026 Reactorcoremeltdown
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package space.rcmd.android.sizzle.io
+
+import space.rcmd.android.sizzle.model.Arrangement
+import space.rcmd.android.sizzle.model.Pitch
+import space.rcmd.android.sizzle.model.Project
+import space.rcmd.android.sizzle.model.TimeSignature
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/** Verifies the `.sng` reader/writer against the reference desktop format. */
+class SngFormatTest {
+
+    private val reference = """
+        version 1
+        bpm 120
+        sig 4 4
+
+        block A 16 4
+        roll ####
+        track T1 0
+        0 C-4 64 01
+        4 E-4 .. ..
+        8 OFF .. ..
+        endblock
+    """.trimIndent()
+
+    @Test
+    fun parsesReferenceExample() {
+        val p = SngFormat.importInto(Project(), reference)
+
+        assertEquals(120f, p.tempoBpm, 0.001f)
+        assertEquals(TimeSignature.FOUR_FOUR, p.timeSignature)
+
+        val block = p.patterns[0]
+        assertEquals("A", block.name)
+        assertEquals(16, block.length)
+
+        val c0 = block.cell(0, 0)
+        assertEquals(Pitch.parse("C-4"), c0.note)
+        assertEquals(0x64, c0.velocity)   // velocity is hexadecimal
+        assertEquals(1, c0.channel)
+
+        val c4 = block.cell(0, 4)
+        assertEquals(Pitch.parse("E-4"), c4.note)
+        assertEquals(0x7F, c4.velocity)   // ".." -> default (full MIDI velocity)
+        assertEquals(1, c4.channel)       // ".." -> inherit track channel (0 -> 1)
+
+        assertTrue(block.cell(0, 8).isNoteOff)
+
+        // roll "####" enables block 0 on beats 0..3 of its own lane.
+        for (beat in 0..3) assertNotEquals(Arrangement.EMPTY, p.arrangement.patternAt(0, beat))
+        assertEquals(Arrangement.EMPTY, p.arrangement.patternAt(0, 4))
+    }
+
+    @Test
+    fun roundTripsNotesAndRoll() {
+        val p = Project()
+        p.tempoBpm = 140f
+        p.timeSignature = TimeSignature.FIVE_FOUR
+        p.patterns[0].cell(0, 0).apply { note = 60; velocity = 0x40; channel = 3 }
+        p.patterns[0].cell(1, 5).apply { note = 67; velocity = 0x7F; channel = 2 }
+        p.arrangement.set(0, 0, 0)
+        p.arrangement.set(0, 1, 0)
+
+        val restored = SngFormat.importInto(Project(), SngFormat.export(p))
+
+        assertEquals(140f, restored.tempoBpm, 0.001f)
+        assertEquals(TimeSignature.FIVE_FOUR, restored.timeSignature)
+        restored.patterns[0].cell(0, 0).let {
+            assertEquals(60, it.note); assertEquals(0x40, it.velocity); assertEquals(3, it.channel)
+        }
+        restored.patterns[0].cell(1, 5).let {
+            assertEquals(67, it.note); assertEquals(0x7F, it.velocity); assertEquals(2, it.channel)
+        }
+        assertNotEquals(Arrangement.EMPTY, restored.arrangement.patternAt(0, 0))
+        assertNotEquals(Arrangement.EMPTY, restored.arrangement.patternAt(0, 1))
+    }
+}