feat(discord): add silent message support (SUPPRESS_NOTIFICATIONS flag)

- Add silent option to message tool for Discord
- Passes SUPPRESS_NOTIFICATIONS flag (4096) to Discord API
- Threads silent param through entire outbound chain:
  - message-action-runner.ts
  - outbound-send-service.ts
  - message.ts
  - deliver.ts
  - discord outbound adapter
  - send.outbound.ts
  - send.shared.ts

Usage: message tool with silent=true suppresses push/desktop notifications

src/channels/plugins/outbound/discord.ts

@@ -6,22 +6,24 @@ export const discordOutbound: ChannelOutboundAdapter = {
   chunker: null,
   textChunkLimit: 2000,
   pollMaxOptions: 10,
-  sendText: async ({ to, text, accountId, deps, replyToId }) => {
+  sendText: async ({ to, text, accountId, deps, replyToId, silent }) => {
     const send = deps?.sendDiscord ?? sendMessageDiscord;
     const result = await send(to, text, {
       verbose: false,
       replyTo: replyToId ?? undefined,
       accountId: accountId ?? undefined,
+      silent: silent ?? undefined,
     });
     return { channel: "discord", ...result };
   },
-  sendMedia: async ({ to, text, mediaUrl, accountId, deps, replyToId }) => {
+  sendMedia: async ({ to, text, mediaUrl, accountId, deps, replyToId, silent }) => {
     const send = deps?.sendDiscord ?? sendMessageDiscord;
     const result = await send(to, text, {
       verbose: false,
       mediaUrl,
       replyTo: replyToId ?? undefined,
       accountId: accountId ?? undefined,
+      silent: silent ?? undefined,
     });
     return { channel: "discord", ...result };
   },

src/channels/plugins/types.adapters.ts

@@ -80,6 +80,7 @@ export type ChannelOutboundContext = {
   threadId?: string | number | null;
   accountId?: string | null;
   deps?: OutboundSendDeps;
+  silent?: boolean;
 };
 
 export type ChannelOutboundPayloadContext = ChannelOutboundContext & {