feat(api): add API routes with full state wiring and integration test fixtures

- Add /api routes for agents and proxy resources

- Wire all services into ApiState in service/mod.rs

- Update route tests with all mock services

apps/nxmesh-master/src/routes/api/agents/update_agent.rs

@@ -0,0 +1,62 @@
+use std::sync::Arc;
+
+use axum::{
+    Json,
+    extract::{Path, State},
+    http::StatusCode,
+    response::IntoResponse,
+};
+use serde::Deserialize;
+use tracing::error;
+
+use crate::{
+    routes::api::{agents::dto::AgentInfo, error::AppError},
+    service::agent::{AgentService, State as AgentState, UpdateAgentRecord},
+};
+
+#[derive(Debug, Deserialize)]
+pub struct UpdateAgentRequest {
+    #[serde(default)]
+    pub name: Option<String>,
+    #[serde(default)]
+    pub ip_address: Option<String>,
+    #[serde(default)]
+    pub state: Option<AgentState>,
+    #[serde(default)]
+    pub deployment_mode: Option<String>,
+    #[serde(default)]
+    pub labels: Option<serde_json::Value>,
+}
+
+pub async fn update_agent_handler(
+    State(agent_service): State<Arc<dyn AgentService>>,
+    Path(id): Path<uuid::Uuid>,
+    Json(body): Json<UpdateAgentRequest>,
+) -> Result<impl IntoResponse, AppError> {
+    if let Some(ref name) = body.name {
+        if name.trim().is_empty() {
+            return Err(AppError::BadRequest("name must not be empty".to_string()));
+        }
+    }
+
+    let rec = UpdateAgentRecord {
+        name: body.name,
+        ip_address: body.ip_address,
+        state: body.state,
+        deployment_mode: body.deployment_mode,
+        labels: body.labels,
+    };
+
+    let agent = agent_service.update(id, &rec).await.map_err(|err| {
+        error!("Failed to update agent: {}", err);
+        AppError::InternalServerError
+    })?;
+
+    match agent {
+        Some(agent) => Ok((
+            StatusCode::OK,
+            Json(serde_json::json!({"agent": AgentInfo::from(agent)})),
+        )),
+        None => Err(AppError::NotFound),
+    }
+}