feat: deliver first successful FridaBox MVP

Integrate Frida Gadget into BlackBox guest startup, add the host workflow and controller tooling, and validate the complete sample hook flow on ARM64 Android 16.

sample-guest/src/main/java/com/qm4rs/fridabox/sample/Target.java

@@ -0,0 +1,10 @@
+package com.qm4rs.fridabox.sample;
+
+public final class Target {
+    private Target() {
+    }
+
+    public static int add(int a, int b) {
+        return a + b;
+    }
+}