feat: Prepare for code modularization and cleanup

- Archive old documentation and test files to `docs/archive/` and `local_tests/`.
- Remove various temporary and old files from the project root.
- Add `nekocode-rust` analysis tool and its output files (`nekocode/`, `.nekocode_sessions/`, `analysis.json`).
- Minor updates to `apps/chip8_nyash/chip8_emulator.nyash` and `local_tests` files.

This commit cleans up the repository and sets the stage for further code modularization efforts, particularly in the `src/interpreter` and `src/parser` modules, based on recent analysis.

local_tests/test_simple_weak_ref.nyash

@@ -0,0 +1,79 @@
+// Simple weak reference test for Phase 10.2
+
+// Test CPU with fini
+box TestCPU {
+    init { memory, name }
+    
+    TestCPU() {
+        me.name = "TestCPU"
+        print("CPU initialized: " + me.name)
+    }
+    
+    fini() {
+        print("CPU fini called - cleaning up memory")
+        if (me.memory != null) {
+            me.memory.cleanup()
+        }
+        print("CPU fini complete")
+    }
+}
+
+// Test Memory with weak reference
+box TestMemory {
+    init { data, weak cpu_ref }
+    
+    TestMemory(cpu_instance) {
+        me.data = new ArrayBox()
+        me.data.push("test_data")
+        me.cpu_ref = cpu_instance  // This will be automatically downgraded to weak
+        print("Memory initialized with weak CPU reference")
+    }
+    
+    read_data() {
+        if (me.cpu_ref != null) {
+            print("CPU is alive - returning data")
+            return me.data.get(0)
+        } else {
+            print("CPU is destroyed - access blocked")
+            return null
+        }
+    }
+    
+    cleanup() {
+        print("Memory cleanup called")
+        me.data.clear()
+    }
+}
+
+// Main test
+static box Main {
+    init { console }
+    
+    main() {
+        me.console = new ConsoleBox()
+        me.console.log("🧪 Testing weak references and fini propagation")
+        
+        // Create CPU and Memory
+        local cpu = new TestCPU()
+        
+        local memory = new TestMemory(cpu)
+        
+        // Link memory to CPU for fini propagation
+        cpu.memory = memory
+        
+        // Test 1: Normal operation
+        me.console.log("Test 1: Normal operation")
+        local result1 = memory.read_data()
+        me.console.log("Read result: " + result1)
+        
+        // Test 2: After CPU destruction
+        me.console.log("Test 2: Destroying CPU...")
+        cpu.fini()
+        cpu = null
+        
+        local result2 = memory.read_data()
+        me.console.log("Read after CPU destruction: " + result2)
+        
+        return "Test complete"
+    }
+}