refactor(hermes): delegate deep config to Hermes Web UI

Slim the Hermes surface in CC Switch to match its core positioning —
cross-client provider switching and shared MCP/prompts/skills — and
delegate deep configuration (model, agent, env, skills, cron, logs)
to the Hermes Web UI at http://127.0.0.1:9119.

- Drop AgentPanel/EnvPanel/ModelPanel and their mutation commands,
  hooks, types, and i18n keys across zh/en/ja.
- Add open_hermes_web_ui Tauri command that probes /api/status and
  launches the URL in the system browser. Hermes injects its own
  session token into the returned HTML, so CC Switch doesn't need
  to touch auth.
- Surface the launcher from the Hermes toolbar and the health banner
  via a shared useOpenHermesWebUI() hook; the offline error code is
  defined once per side and referenced across the contract.
- Keep read-only access to model.provider so ProviderList can still
  highlight the active supplier; apply_switch_defaults continues to
  write the top-level model section when switching providers.

Net diff: +152 / -1253.

src-tauri/src/commands/hermes.rs

@@ -1,8 +1,15 @@
-use tauri::State;
+use std::time::Duration;
+use tauri::{AppHandle, State};
+use tauri_plugin_opener::OpenerExt;
 
 use crate::hermes_config;
 use crate::store::AppState;
 
+/// Error string returned when `open_hermes_web_ui` cannot reach the Hermes
+/// FastAPI server. Kept in sync with the `HERMES_WEB_OFFLINE_ERROR` constant
+/// in `src/hooks/useHermes.ts` so the frontend can branch on it.
+const HERMES_WEB_OFFLINE_ERROR: &str = "hermes_web_offline";
+
 // ============================================================================
 // Hermes Provider Commands
 // ============================================================================
@@ -43,52 +50,60 @@ pub fn scan_hermes_config_health() -> Result<Vec<hermes_config::HermesHealthWarn
 // Model Configuration Commands
 // ============================================================================
 
-/// Get Hermes model config (model section of config.yaml)
+/// Get Hermes model config (model section of config.yaml). Read-only — writes
+/// happen implicitly through `apply_switch_defaults` when switching providers.
 #[tauri::command]
 pub fn get_hermes_model_config() -> Result<Option<hermes_config::HermesModelConfig>, String> {
     hermes_config::get_model_config().map_err(|e| e.to_string())
 }
 
-/// Set Hermes model config (model section of config.yaml)
-#[tauri::command]
-pub fn set_hermes_model_config(
-    model: hermes_config::HermesModelConfig,
-) -> Result<hermes_config::HermesWriteOutcome, String> {
-    hermes_config::set_model_config(&model).map_err(|e| e.to_string())
-}
-
 // ============================================================================
-// Agent Configuration Commands
+// Hermes Web UI launcher
 // ============================================================================
 
-/// Get Hermes agent config (agent section of config.yaml)
+/// Probe the local Hermes Web UI (FastAPI) and open it in the system browser.
+///
+/// Port discovery priority:
+///   1. `HERMES_WEB_PORT` environment variable
+///   2. Default 9119
+///
+/// Hermes wraps all `/api/*` routes in a Bearer-token middleware, so a GET
+/// against `/api/status` returning **either 200 or 401** confirms the server
+/// is live. The session token lives only in the Hermes process memory and is
+/// injected into the returned HTML via `window.__HERMES_SESSION_TOKEN__`, so
+/// there is no need (and no way) for CC Switch to inject it — we just open
+/// the URL and let Hermes handle auth.
 #[tauri::command]
-pub fn get_hermes_agent_config() -> Result<Option<hermes_config::HermesAgentConfig>, String> {
-    hermes_config::get_agent_config().map_err(|e| e.to_string())
-}
+pub async fn open_hermes_web_ui(app: AppHandle, path: Option<String>) -> Result<(), String> {
+    let port = std::env::var("HERMES_WEB_PORT")
+        .ok()
+        .and_then(|raw| raw.trim().parse::<u16>().ok())
+        .unwrap_or(9119);
 
-/// Set Hermes agent config (agent section of config.yaml)
-#[tauri::command]
-pub fn set_hermes_agent_config(
-    agent: hermes_config::HermesAgentConfig,
-) -> Result<hermes_config::HermesWriteOutcome, String> {
-    hermes_config::set_agent_config(&agent).map_err(|e| e.to_string())
-}
+    let base = format!("http://127.0.0.1:{port}");
 
-// ============================================================================
-// Env Configuration Commands
-// ============================================================================
+    // Probe /api/status with a short timeout. Hermes returns 200 when open or
+    // 401 when the session token is required — either way the server is live.
+    // Only a connection error / timeout means the server isn't running.
+    let probe_url = format!("{base}/api/status");
+    let client = reqwest::Client::builder()
+        .timeout(Duration::from_millis(1200))
+        .no_proxy()
+        .build()
+        .map_err(|e| format!("failed to build probe client: {e}"))?;
 
-/// Get Hermes env config (.env file)
-#[tauri::command]
-pub fn get_hermes_env() -> Result<hermes_config::HermesEnvConfig, String> {
-    hermes_config::read_env().map_err(|e| e.to_string())
-}
+    match client.get(&probe_url).send().await {
+        Ok(_) => {}
+        Err(_) => return Err(HERMES_WEB_OFFLINE_ERROR.to_string()),
+    }
 
-/// Set Hermes env config (.env file)
-#[tauri::command]
-pub fn set_hermes_env(
-    env: hermes_config::HermesEnvConfig,
-) -> Result<hermes_config::HermesWriteOutcome, String> {
-    hermes_config::write_env(&env).map_err(|e| e.to_string())
+    let target = match path.as_deref() {
+        Some(p) if p.starts_with('/') => format!("{base}{p}"),
+        Some(p) if !p.is_empty() => format!("{base}/{p}"),
+        _ => format!("{base}/"),
+    };
+
+    app.opener()
+        .open_url(&target, None::<String>)
+        .map_err(|e| format!("failed to open Hermes Web UI: {e}"))
 }