impl: load the public key from a resource file

Initially I thought about embedding it as a const string in the code
but the string is too big, best to save it as resource file.
The code changes are mostly related to loading the key from the file.

Author: fioan89

src/main/kotlin/com/coder/toolbox/cli/gpg/GPGVerifier.kt

@@ -18,6 +18,7 @@ import java.io.ByteArrayInputStream
 import java.nio.file.Files
 import java.nio.file.Path
 
+
 class GPGVerifier(
     private val context: CoderToolboxContext,
 ) {
@@ -48,23 +49,29 @@ class GPGVerifier(
     }
 
     private fun getCoderPublicKeyRing(): PGPPublicKeyRing {
-        return try {
-            getDefaultCoderPublicKeyRing()
+        try {
+            val coderPublicKey = javaClass.getResourceAsStream("/META-INF/trusted-keys/pgp-public.key")
+                ?.readAllBytes() ?: throw IllegalStateException("Trusted public key not found")
+            return loadPublicKeyRing(coderPublicKey)
         } catch (e: Exception) {
             throw PGPException("Failed to load Coder public GPG key", e)
         }
     }
 
-    private fun getDefaultCoderPublicKeyRing(): PGPPublicKeyRing {
-        val coderPublicKey = """
-            -----BEGIN PGP PUBLIC KEY BLOCK-----
-            
-            # Replace this with Coder's actual public key
-            
-            -----END PGP PUBLIC KEY BLOCK-----
-        """.trimIndent()
-
-        return loadPublicKeyRing(coderPublicKey.toByteArray())
+    /**
+     * Load public key ring from bytes
+     */
+    fun loadPublicKeyRing(publicKeyBytes: ByteArray): PGPPublicKeyRing {
+        return try {
+            val keyInputStream = ArmoredInputStream(ByteArrayInputStream(publicKeyBytes))
+            val keyRingCollection = PGPPublicKeyRingCollection(
+                PGPUtil.getDecoderStream(keyInputStream),
+                JcaKeyFingerprintCalculator()
+            )
+            keyRingCollection.keyRings.next()
+        } catch (e: Exception) {
+            throw PGPException("Failed to load public key ring", e)
+        }
     }
 
     /**
@@ -103,20 +110,4 @@ class GPGVerifier(
             return Failed(e)
         }
     }
-
-    /**
-     * Load public key ring from bytes
-     */
-    fun loadPublicKeyRing(publicKeyBytes: ByteArray): PGPPublicKeyRing {
-        return try {
-            val keyInputStream = ArmoredInputStream(ByteArrayInputStream(publicKeyBytes))
-            val keyRingCollection = PGPPublicKeyRingCollection(
-                PGPUtil.getDecoderStream(keyInputStream),
-                JcaKeyFingerprintCalculator()
-            )
-            keyRingCollection.keyRings.next()
-        } catch (e: Exception) {
-            throw PGPException("Failed to load public key ring", e)
-        }
-    }
 }