Correct stale docs: no resume cursor, no home-channel fallback

Two README claims had outlived their truth:

- 'Resume cursor support' - protocol v1 reserves resume_cursor and the
  adapter carries no such state; reconnects rely on duplicate-event
  suppression, and events missed during downtime are simply gone.
- 'First joined room' as the CHATTO_HOME_CHANNEL default (env table,
  Home Channel section, after-install.md step 2 and the plugin.yaml
  wizard prompt) - nothing implements that fallback. Unset means
  context-less cron/notification deliveries have no Chatto target and
  are not sent.

README.md

@@ -162,7 +162,7 @@ gateway:
 | `CHATTO_LOGIN` | Yes* | — | Chatto username (login) |
 | `CHATTO_PASSWORD` | Yes* | — | Chatto password |
 | `CHATTO_TOKEN` | No | — | Existing bearer token — alternative to login/password |
-| `CHATTO_HOME_CHANNEL` | No | First joined room | Default delivery target for cron/notification output when there is no inbound conversation context to reply into. Not exempt from the mention lists. |
+| `CHATTO_HOME_CHANNEL` | No | _(none)_ | Default delivery target for cron/notification output when there is no inbound conversation context to reply into. Without it, context-less deliveries have no Chatto target and are not sent. Not exempt from the mention lists. |
 | `CHATTO_ALLOWED_USERS` | No | _(deny all)_ | Comma-separated Chatto logins (or user IDs) allowed to talk to the agent. Exact match, case-sensitive. |
 | `CHATTO_ALLOW_ALL_USERS` | No | `false` | Allow any Chatto user to talk to the agent (`true`/`false`) |
 | `CHATTO_REQUIRE_MENTION_ROOMS` | No | _(silent everywhere)_ | Comma-separated room IDs where Hermes answers only when addressed (`@name`, `@all`, `@here`). A room on neither mention list stays silent. |
@@ -327,7 +327,7 @@ The home channel is the default outbound target for proactive messages — cron
 - `CHATTO_HOME_CHANNEL` env var (room ID)
 - `config.yaml` → `gateway.platforms.chatto.extra.home_channel`
 
-If unset, the first joined room is used as the default home channel. The home channel follows the same participation rules as any room: a silent home channel still receives cron/notification posts, but the bot converses there only if it is listed in one of the mention lists too.
+Without a set home channel, context-less cron/notification deliveries have no Chatto target and are not sent — set one if you plan to use Hermes' proactive output. The home channel follows the same participation rules as any room: a silent home channel still receives cron/notification posts, but the bot converses there only if it is listed in one of the mention lists too.
 
 ### Managing Rooms over DM
 
@@ -438,7 +438,7 @@ grep -i "chatto\|websocket\|realtime" ~/.hermes/logs/gateway.log | tail -30
 
 - **Self-hosted friendly**: Works with any self-hosted Chatto instance. No cloud account or subscription required.
 - **Minimal dependencies**: Only requires `chattolib[realtime]>=0.4.20.post1`, which is vendored — nothing to install.
-- **Resume cursor support**: On reconnect, the adapter resumes from the last event cursor, so no messages are lost or replayed during transient disconnects.
+- **No message backfill**: Events missed while the gateway is down are gone — Chatto keeps no replay for the bot. Redelivered events after a reconnect are recognised and processed only once; anything genuinely new starts from the moment of reconnection.
 
 ## License
 

after-install.md

@@ -38,8 +38,9 @@ can live in either file. Environment variables take precedence over
    conversation context to reply into — the default outbound target, nothing
    more. It follows the same participation rules as any room: a silent room
    stays quiet, so list it in one of the mention room lists (see step 5) too
-   if the bot should also converse in it. If unset (the usual case — the
-   installer only asks when you enter one), the first joined room is used:
+   if the bot should also converse in it. If unset, context-less deliveries
+   have no Chatto target and are not sent — set one if you plan to use
+   Hermes' proactive output:
 
    ```
    CHATTO_HOME_CHANNEL=ROOM_ID_HERE

plugin.yaml

@@ -29,7 +29,7 @@ optional_env:
     prompt: "Existing bearer token (or empty)"
     password: true
   - name: CHATTO_HOME_CHANNEL
-    description: "Room ID for cron / notification delivery (defaults to the first joined room)"
+    description: "Room ID for cron / notification delivery (default: none — context-less deliveries are not sent without it)"
     prompt: "Home room ID (or empty)"
     password: false
   # Asked before CHATTO_ALLOWED_USERS: a "yes" here makes the user list moot,