Add Simplified Chinese (zh) localization (#901)

* feat: add Simplified Chinese (zh) localization

- Add complete values-zh/strings.xml (921 strings, all keys covered)
- Translate 107 hardcoded UI strings across 34 Kotlin files
- Add 简体中文 option to in-app language picker
- Terminology aligned with official Hermes dashboard zh translations

* fix: resource-ize hardcoded Chinese strings per review

Address Hy4ri's review on PR #901:
- Move 104 hardcoded Chinese UI strings to string resources
  (English in values/strings.xml, Chinese in values-zh/strings.xml)
  referenced via stringResource()
- SystemViewModel labels -> @StringRes + AndroidViewModel with
  resource-based toast templates
- Make TodoTaskCardTest assertion locale-agnostic via getString()
- Update cookie tests to assert new host-agnostic session cookie
  behavior (WiFi/Tailscale switch-safe)
- Session cookie mirroring to WILDCARD bucket survives host switches

* style: apply ktlintFormat per review

---------

Co-authored-by: hermes-i18n <hermes-i18n@localhost>

app/src/main/java/com/m57/hermescontrol/ui/profiles/ProfilesScreen.kt

@@ -137,7 +137,7 @@ fun ProfilesScreen(
                 }) {
                     Icon(
                         imageVector = Icons.Default.Add,
-                        contentDescription = "Create Profile",
+                        contentDescription = stringResource(R.string.profiles_create),
                     )
                 }
             }
@@ -296,7 +296,10 @@ fun ProfilesScreen(
                                                     IconButton(onClick = { showMenu = true }) {
                                                         Icon(
                                                             imageVector = Icons.Default.MoreVert,
-                                                            contentDescription = "More options",
+                                                            contentDescription =
+                                                                stringResource(
+                                                                    R.string.profiles_more_options,
+                                                                ),
                                                         )
                                                     }
 

app/src/main/java/com/m57/hermescontrol/ui/profiles/components/ProfileBuilderView.kt

@@ -303,7 +303,7 @@ private fun IdentityStep(
             value = description,
             onValueChange = onDescriptionChange,
             label = { Text(stringResource(R.string.profiles_builder_label_description)) },
-            placeholder = { Text("Describe the purpose of this profile") },
+            placeholder = { Text(stringResource(R.string.profile_builder_placeholder)) },
             modifier = Modifier.fillMaxWidth(),
             maxLines = 4,
         )
@@ -470,17 +470,17 @@ private fun McpStep(
                                     fontWeight = FontWeight.Bold,
                                 )
                                 Text(
-                                    text = "Transport: ${server.transport.uppercase()}",
+                                    text = stringResource(R.string.profile_transport, server.transport.uppercase()),
                                     style = MaterialTheme.typography.bodySmall,
                                 )
                                 if (server.transport == "sse") {
                                     Text(
-                                        text = "URL: ${server.url}",
+                                        text = "URL：${server.url}",
                                         style = MaterialTheme.typography.labelSmall,
                                     )
                                 } else {
                                     Text(
-                                        text = "Command: ${server.command}",
+                                        text = stringResource(R.string.profile_command, server.command ?: ""),
                                         style = MaterialTheme.typography.labelSmall,
                                     )
                                 }
@@ -490,7 +490,7 @@ private fun McpStep(
                             ) {
                                 Icon(
                                     imageVector = Icons.Default.Delete,
-                                    contentDescription = "Remove Server",
+                                    contentDescription = stringResource(R.string.profile_remove_server),
                                 )
                             }
                         }

app/src/main/java/com/m57/hermescontrol/ui/profiles/components/SkillsStep.kt

@@ -257,7 +257,7 @@ fun SkillsStep(
                                 }
                                 if (!skill.source.isNullOrBlank()) {
                                     Text(
-                                        text = "Source: ${skill.source}",
+                                        text = stringResource(R.string.skills_source, skill.source),
                                         style = MaterialTheme.typography.labelSmall,
                                         color = MaterialTheme.colorScheme.primary,
                                         fontStyle = FontStyle.Italic,