Fix emote targeting and grammar; add tests

Prevent 'system' mis-target via peerID-derived display name in actions sheet. Correct /hug and /slap usage/error grammar by passing base command name. Improve geohash nickname resolution to match displayName with #suffix. Add CommandProcessor tests.

bitchatTests/CommandProcessorTests.swift

@@ -0,0 +1,42 @@
+import XCTest
+@testable import bitchat
+
+final class CommandProcessorTests: XCTestCase {
+
+    @MainActor
+    func test_slap_notFoundGrammar() {
+        let processor = CommandProcessor(chatViewModel: nil, meshService: nil)
+        let result = processor.process("/slap @system")
+        switch result {
+        case .error(let message):
+            XCTAssertEqual(message, "cannot slap system: not found")
+        default:
+            XCTFail("Expected error result")
+        }
+    }
+
+    @MainActor
+    func test_hug_notFoundGrammar() {
+        let processor = CommandProcessor(chatViewModel: nil, meshService: nil)
+        let result = processor.process("/hug @system")
+        switch result {
+        case .error(let message):
+            XCTAssertEqual(message, "cannot hug system: not found")
+        default:
+            XCTFail("Expected error result")
+        }
+    }
+
+    @MainActor
+    func test_slap_usageMessage() {
+        let processor = CommandProcessor(chatViewModel: nil, meshService: nil)
+        let result = processor.process("/slap")
+        switch result {
+        case .error(let message):
+            XCTAssertEqual(message, "usage: /slap <nickname>")
+        default:
+            XCTFail("Expected error result for usage message")
+        }
+    }
+}
+