sequenceDiagram
    participant Server as Server
    participant Scheduler as Periodic Scheduler
    participant Checker as updateChecker
    participant Store as upgradeStore (Cache)
    participant Template as Template Functions

    Note over Server,Template: Server Startup
    Server->>Checker: create updateChecker{store: upgradeStore}
    Server->>Server: startPeriodicUpdateCheck(ctx)
    
    Note over Scheduler,Store: Initial Check + Scheduling
    Server->>Checker: GetUpdateInfo()
    Checker->>Store: read cache
    Store-->>Checker: cached values
    Checker-->>Server: (updateAvailable, latestVersion)
    Server->>Store: update cache (initial check)
    
    Server->>Scheduler: schedule periodic checks at CacheTTL
    
    Note over Scheduler,Template: Periodic Update Flow
    loop Every CacheTTL
        Scheduler->>Checker: GetUpdateInfo()
        Checker->>Store: read current cache
        Store-->>Checker: cached values
        Checker-->>Scheduler: (updateAvailable, latestVersion)
        Scheduler->>Store: update cache with latest
    end
    
    Note over Template,Store: Template Rendering
    Template->>Checker: GetUpdateInfo()
    Checker->>Store: read cache
    Store-->>Checker: cached values
    Checker-->>Template: (updateAvailable, latestVersion)
    Template-->>Template: render with update info