Ship Composio as a built-in integration and trim Settings

- Resolve the API key from cred.txt at the project root in development
  and the packaged resources directory in production; the file is the
  source of truth, so a rotated key replaces the stored one. Fixes the
  401 packaged builds hit when a stale database key won.
- Remove the user-facing Composio key editor; the key ships with the
  product and is not configurable.
- Remove the Migration console from Settings.
- Remove the Connectors and Home refresh buttons; connector statuses
  sync when the page opens.

src/preload/index.ts

@@ -82,7 +82,6 @@ const api: DesktopApi = {
   setLegalHoldState: (input) => invoke(IPC_CHANNELS.setLegalHoldState, input),
   createRetentionFreeze: (input) => invoke(IPC_CHANNELS.createRetentionFreeze, input),
   setRetentionFreezeState: (input) => invoke(IPC_CHANNELS.setRetentionFreezeState, input),
-  saveComposioSettings: (input) => invoke(IPC_CHANNELS.saveComposioSettings, input),
   listComposioToolkits: (input) => invoke(IPC_CHANNELS.listComposioToolkits, input),
   connectComposioToolkit: (input) => invoke(IPC_CHANNELS.connectComposioToolkit, input),
   refreshComposioAccounts: (input) => invoke(IPC_CHANNELS.refreshComposioAccounts, input),