refactor: eliminate ViewModel struct to simplify architecture

Replace separate ViewModel struct with Model itself by:
- Using #[serde(skip_serializing)] on auth_token field in Model
- Updating App trait to use Model as ViewModel type
- Removing the manual view() function that copied fields
- Removing duplicate ViewModel struct definition

Benefits:
- Eliminates ~30 lines of duplicate code
- Removes manual field-by-field copying in view()
- Simplifies architecture with single source of truth
- Auth token automatically excluded from serialization
- Zero functional changes, all tests pass

Files modified:
- src/app/src/model.rs: Removed ViewModel, added skip_serializing
- src/app/src/lib.rs: Use Model as ViewModel, simplified view()
- src/app/src/update/mod.rs: Removed manual view() function

Signed-off-by: Jan Zachmann <50990105+JanZachmann@users.noreply.github.com>

Author: JanZachmann

src/app/src/lib.rs

@@ -17,7 +17,7 @@ use crux_http::Http;
 // Re-export core types
 pub use crate::capabilities::centrifugo::{CentrifugoOperation, CentrifugoOutput};
 pub use crate::events::Event;
-pub use crate::model::{Model, ViewModel};
+pub use crate::model::Model;
 pub use crate::types::*;
 pub use crux_http::Result as HttpResult;
 
@@ -52,7 +52,7 @@ pub struct App;
 impl crux_core::App for App {
     type Event = Event;
     type Model = Model;
-    type ViewModel = ViewModel;
+    type ViewModel = Model;
     type Capabilities = Capabilities;
     type Effect = Effect;
 
@@ -66,7 +66,7 @@ impl crux_core::App for App {
     }
 
     fn view(&self, model: &Self::Model) -> Self::ViewModel {
-        update::view(model)
+        model.clone()
     }
 }
 

src/app/src/model.rs

@@ -3,6 +3,7 @@ use serde::{Deserialize, Serialize};
 use crate::types::*;
 
 /// Application Model - the complete state
+/// Also serves as the ViewModel when serialized (auth_token is excluded)
 #[derive(Debug, Default, Serialize, Deserialize, Clone, PartialEq, Eq)]
 pub struct Model {
     // Device state
@@ -15,6 +16,8 @@ pub struct Model {
     pub healthcheck: Option<HealthcheckInfo>,
 
     // Authentication state
+    /// Internal auth token - not serialized to the view
+    #[serde(skip_serializing)]
     pub auth_token: Option<String>,
     pub is_authenticated: bool,
     pub requires_password_set: bool,
@@ -27,23 +30,3 @@ pub struct Model {
     // WebSocket state
     pub is_connected: bool,
 }
-
-/// View Model - what the UI needs to render
-#[derive(Debug, Default, Serialize, Deserialize, Clone, PartialEq, Eq)]
-pub struct ViewModel {
-    pub system_info: Option<SystemInfo>,
-    pub network_status: Option<NetworkStatus>,
-    pub online_status: Option<OnlineStatus>,
-    pub factory_reset: Option<FactoryReset>,
-    pub update_validation_status: Option<UpdateValidationStatus>,
-    pub timeouts: Option<Timeouts>,
-    pub healthcheck: Option<HealthcheckInfo>,
-
-    pub is_authenticated: bool,
-    pub requires_password_set: bool,
-
-    pub is_loading: bool,
-    pub error_message: Option<String>,
-    pub success_message: Option<String>,
-    pub is_connected: bool,
-}

src/app/src/update/mod.rs

@@ -6,7 +6,7 @@ mod websocket;
 use crux_core::{render::render, Command};
 
 use crate::events::Event;
-use crate::model::{Model, ViewModel};
+use crate::model::Model;
 use crate::Effect;
 
 /// Main update dispatcher - routes events to domain-specific handlers
@@ -62,22 +62,3 @@ pub fn update(event: Event, model: &mut Model) -> Command<Effect, Event> {
         Event::ClearError | Event::ClearSuccess => ui::handle(event, model),
     }
 }
-
-/// Convert Model to ViewModel for rendering
-pub fn view(model: &Model) -> ViewModel {
-    ViewModel {
-        system_info: model.system_info.clone(),
-        network_status: model.network_status.clone(),
-        online_status: model.online_status.clone(),
-        factory_reset: model.factory_reset.clone(),
-        update_validation_status: model.update_validation_status.clone(),
-        timeouts: model.timeouts.clone(),
-        healthcheck: model.healthcheck.clone(),
-        is_authenticated: model.is_authenticated,
-        requires_password_set: model.requires_password_set,
-        is_loading: model.is_loading,
-        error_message: model.error_message.clone(),
-        success_message: model.success_message.clone(),
-        is_connected: model.is_connected,
-    }
-}