refactor(web): switch dashboard auth from tokens to passwords (#2608)

- replace token-based launcher auth with password-based login and sessions
- migrate legacy launcher_token values into bcrypt-backed password storage
- add one-shot local auto-login bootstrap
- update config UI, i18n strings, docs, and auth-related tests

web/frontend/src/api/system.ts

@@ -11,7 +11,6 @@ export interface LauncherConfig {
   port: number
   public: boolean
   allowed_cidrs: string[]
-  launcher_token: string
 }
 
 export interface SystemVersionInfo {