feat: drop the typed first-message hint from the Discord bridge (#741)

Owner decision. Typing the note into a brand-new non-Claude tab spent a model
turn per tab and, for a spawned worker or a scheduled run, landed with the first
real prompt. Claude keeps its hint through the system prompt, and every other CLI
is told nothing. The setting goes with the path it gated: sessionIdle, the fresh
set, isHintableSession and the session:idle wiring. sendInput loses `fromUser`,
which was only ever false for the hint, and the deps test pins that a reply is a
person's own input.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/wiki/Discord-Bridge.md

@@ -47,7 +47,6 @@ only), never in the shared settings, and never shown again once saved.
 | @ ping                                   | Never, critical events only, every post     | Critical only   |
 | Which events                             | Needs attention, or everything              | Needs attention |
 | Tell Claude how to reach you             | On or off                                   | On              |
-| Also tell other CLIs, as a first message | On or off                                   | Off             |
 
 A finished turn, and an error, is posted as the CLI's whole last message, with its formatting and questions
 kept, split over several posts if it is long. A shell, and permission or question dialogs, show the last lines
@@ -69,8 +68,7 @@ permission prompt, a question, an error, or a post an agent marked urgent.
 An agent only posts deliberately if it knows it can:
 
 - **Claude** is launched with the instruction as part of its system prompt (**Tell Claude how to reach you**, on by default), so nothing shows in the chat. This reaches local tabs only (remote and Docker tabs have no `codeman` command).
-- **Every other CLI** is told only if you turn on **Also tell other CLIs, as a first message** (off by default: it costs one model turn per tab, and for a spawned worker or a scheduled run it arrives with the first real prompt). Then the same text is sent once, as a message, the first time a brand-new tab goes idle.
-  Restored tabs, shell tabs, and remote (ssh) and Docker tabs (which have no `codeman` command) are never sent it.
+- **Every other CLI** is not told. It can still run `codeman notify` if you tell it to.
 
 Tabs that were already open when you turned the bridge on are not told. The alerts still reach
 Discord for them; only the agent-initiated `codeman notify` habit is missing.