Extract BLE and chat architecture policies (#1324)

Co-authored-by: jack <jackjackbits@users.noreply.github.com>

bitchatTests/Nostr/Base64URLCodingTests.swift

@@ -0,0 +1,30 @@
+import Foundation
+import Testing
+@testable import bitchat
+
+struct Base64URLCodingTests {
+    @Test
+    func encodesWithoutPaddingOrURLUnsafeCharacters() {
+        let encoded = Base64URLCoding.encode(Data([0xff, 0xee, 0xdd, 0xcc]))
+
+        #expect(!encoded.contains("="))
+        #expect(!encoded.contains("+"))
+        #expect(!encoded.contains("/"))
+    }
+
+    @Test
+    func decodesUnpaddedValue() throws {
+        let data = try #require(Base64URLCoding.decode("_-7dzA"))
+
+        #expect(data == Data([0xff, 0xee, 0xdd, 0xcc]))
+    }
+
+    @Test
+    func roundTripsData() throws {
+        let original = Data("hello bitchat".utf8)
+
+        let decoded = try #require(Base64URLCoding.decode(Base64URLCoding.encode(original)))
+
+        #expect(decoded == original)
+    }
+}