```plaintext
%% ntfy-Discord Bridge (ADR-0022)
%% Sequence diagram showing message flow and transformation

sequenceDiagram
    autonumber
    participant S as Notification Source<br/>(CI/Alertmanager)
    participant N as ntfy<br/>Notification Hub
    participant B as ntfy-discord<br/>Go Bridge
    participant D as Discord<br/>Webhook

    Note over S,N: Events published to ntfy topics

    S->>N: POST /gitea-ci<br/>{title, message, priority}

    Note over N,B: SSE subscription for real-time

    N-->>B: SSE JSON stream<br/>{topic, message, priority, tags}

    Note over B: Message transformation

    rect rgb(240, 240, 240)
        B->>B: Map priority to embed color<br/>urgent=red, high=orange<br/>default=blue, low=gray
        B->>B: Format as Discord embed<br/>{embeds: [{title, description, color}]}
    end

    B->>D: POST webhook URL<br/>Discord embed format

    Note over B: Hot-reload support

    rect rgb(230, 245, 230)
        B->>B: fsnotify watches secrets
        B->>B: Reload config without restart
    end

    Note over B,D: Retry with exponential backoff

    alt Webhook fails
        B-->>B: Retry (2s, 4s, 8s...)
        B->>D: Retry POST
    end

    D-->>D: Display in channel

```