Add Classified Briefs 3, 4, and 5 with full firmware and README updates

0x001aa_cb/src/main.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include "pico/stdlib.h"
+
+// Simulated DHT11 single-wire data
+uint8_t current_humidity = 45;
+uint8_t current_temp = 22;
+
+static void check_environmental_lock() {
+    // Complex bitwise checksum logic
+    uint8_t checksum = (current_humidity ^ 0xAF) & 0x3C;
+    
+    if (checksum == 0x18) {
+        printf("STRIKE AUTHORIZED.\r\n");
+    } else {
+        printf("ENVIRONMENT SUB-OPTIMAL. HOLDING.\r\n");
+    }
+}
+
+int main(void) {
+    stdio_init_all();
+    while (true) {
+        check_environmental_lock();
+        sleep_ms(1000);
+    }
+}