feat(cw): port Morse Expert 1.15 CW decoder engine (feature:cw compiles)

Full port of the CW/Morse decoder from Morse Expert 1.15
(com.ve3nea.morse_expert), preserving obfuscated class names and logic.
Ads (gms.ads), billing (BillingClient), and library code were removed per
user; SettingsActivity deferred to Compose integration.

Ported modules:
- pas.*: decoder engine interface + JNI (libnativedecoderjni.so, armeabi-v7a)
- k3.*: FFT library (pseudo-enum q rewritten from smali; sun.misc stubs
  for Unsafe/Cleaner since Android lacks them; FFT path uses float[] branch)
- i3.*, g3.*, j3.*, s.*, d1.AbstractC1518b: DSP/sin-cos tables (long[] tables
  f/f11589g restored from smali)
- H2.a/b: audio capture + decode control core (jadx catch-block illusions
  cleaned per smali; recording try/catch restored around write block)
- J2.a/b: waterfall OpenGL renderer + palette (r10 = anchor color per smali)
- E2.g: waterfall touch frequency picker (height = ScaleView per smali)
- B0.b/B.RunnableC0001b: status-bar + decoded-text UI runnables (real
  constructors recovered from smali)
- MainActivity → controller class (Activity injected; immersive status bar
  inlined); C1646n trimmed to view holder; D.n keeps waterfall texture case
- F2.a: text selection menu (Save/Share)

Verified: :feature:cw:compileDebugJavaWithJavac BUILD SUCCESSFUL.

feature/cw/src/main/java/k3/r.java

@@ -0,0 +1,97 @@
+package k3;
+
+import java.lang.reflect.Field;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import sun.misc.Unsafe;
+
+/* loaded from: classes.dex */
+public abstract class r {
+
+    /* renamed from: a, reason: collision with root package name */
+    public static final Unsafe f12109a;
+
+    static {
+        Object obj = null;
+        try {
+            Class<?> cls = Class.forName("sun.misc.Unsafe");
+            Field declaredField = cls.getDeclaredField("theUnsafe");
+            declaredField.setAccessible(true);
+            obj = declaredField.get(cls);
+        } catch (ClassNotFoundException | IllegalAccessException | IllegalArgumentException | NoSuchFieldException | SecurityException ignored) {
+            // Android 适配: sun.misc.Unsafe 可能不可用(隐藏 API), 静默降级为 null;
+            // 大数组 native 路径(j4 > 1GB)不会在实际解码中触发
+        }
+        f12109a = (Unsafe) obj;
+    }
+
+    public static void a(long j4, long j5, long j6, d dVar, d dVar2) {
+        long j7;
+        if (j4 >= 0 && j4 < dVar.f12102g) {
+            if (j5 >= 0 && j5 < dVar2.f12102g) {
+                if (j6 >= 0) {
+                    if (!dVar2.f12104i) {
+                        long j8 = c.c;
+                        double[][] dArr = g3.c.f11585a;
+                        if (j6 <= j8) {
+                            j8 = j6;
+                        }
+                        int i4 = (int) j8;
+                        if (i4 >= 2 && j6 >= c.f12095d) {
+                            long j9 = j6 / i4;
+                            Future[] futureArr = new Future[i4];
+                            int i5 = 0;
+                            while (i5 < i4) {
+                                long j10 = i5 * j9;
+                                if (i5 == i4 - 1) {
+                                    j7 = j6;
+                                } else {
+                                    j7 = j10 + j9;
+                                }
+                                Future[] futureArr2 = futureArr;
+                                int i6 = i5;
+                                futureArr2[i6] = c.a(new j3.b(j10, j7, j5, j4, dVar2, dVar));
+                                i5 = i6 + 1;
+                                futureArr = futureArr2;
+                            }
+                            try {
+                                c.b(futureArr);
+                                return;
+                            } catch (InterruptedException unused) {
+                                long j11 = j4;
+                                long j12 = j5;
+                                while (j11 < j4 + j6) {
+                                    dVar2.c(j12, dVar.b(j11));
+                                    j11++;
+                                    j12++;
+                                }
+                                return;
+                            } catch (ExecutionException unused2) {
+                                long j13 = j4;
+                                long j14 = j5;
+                                while (j13 < j4 + j6) {
+                                    dVar2.c(j14, dVar.b(j13));
+                                    j13++;
+                                    j14++;
+                                }
+                                return;
+                            }
+                        }
+                        long j15 = j4;
+                        long j16 = j5;
+                        while (j15 < j4 + j6) {
+                            dVar2.c(j16, dVar.b(j15));
+                            j15++;
+                            j16++;
+                        }
+                        return;
+                    }
+                    throw new IllegalArgumentException("Constant arrays cannot be modified.");
+                }
+                throw new IllegalArgumentException("length < 0");
+            }
+            throw new ArrayIndexOutOfBoundsException("destPos < 0 || destPos >= dest.length()");
+        }
+        throw new ArrayIndexOutOfBoundsException("srcPos < 0 || srcPos >= src.length()");
+    }
+}