feat(admin): bot management (list, verify, create, delete)

- Add a Bots admin tab: list/search bots with a dedicated read query
  (users.is_bot, excluded from the accounts list), showing owner and
  system-vs-user type
- Create system bots from the admin via a new bot.create command that
  reuses the existing bot provisioning flow; the token is shown once
- Delete user-created bots via a new bot.delete command backed by a
  dedicated Postgres DeleteBotAccount (revokes sessions, purges private
  state, releases username, drops the bots row, tombstones the user);
  system service bots are rejected
- Verified badge toggling reuses the existing set-verified command
- All write paths go through the dry-run/confirm + audit command pipeline
- Rebuild dist bundle

cmd/telesrv-admin/web/src/api.ts

@@ -1,6 +1,8 @@
 import type {
   AccountDetail,
   AccountListResponse,
+  BotDetail,
+  BotListResponse,
   ChannelDetail,
   ChannelListResponse,
   CommandResult,
@@ -56,6 +58,8 @@ export const api = {
   account: (id: number) => request<AccountDetail>(`/api/accounts/${id}`),
   channels: (params: URLSearchParams) => request<ChannelListResponse>(`/api/channels?${params.toString()}`),
   channel: (id: number) => request<ChannelDetail>(`/api/channels/${id}`),
+  bots: (params: URLSearchParams) => request<BotListResponse>(`/api/bots?${params.toString()}`),
+  bot: (id: number) => request<BotDetail>(`/api/bots/${id}`),
   messages: (params: URLSearchParams) => request<MessageListResponse>(`/api/messages?${params.toString()}`),
   message: (ownerUserID: number, msgID: number) => {
     const params = new URLSearchParams({ owner_user_id: String(ownerUserID), msg_id: String(msgID) });