feat: wire channel mode runtime config and docs

plugin/README.md

@@ -30,6 +30,9 @@ Optional:
 - `channelPoliciesFile` (per-channel overrides in a standalone JSON file)
 - `schedulingIdentifier` (default `➡️`) — moderator handoff identifier
 - `enableDirigentPolicyTool` (default true)
+- `multiMessageStartMarker` (default `↗️`)
+- `multiMessageEndMarker` (default `↙️`)
+- `multiMessagePromptMarker` (default `⤵️`)
 
 Unified optional tool:
 - `dirigent_tools`
@@ -59,6 +62,15 @@ When the current speaker NO_REPLYs, the moderator bot sends: `<@NEXT_USER_ID>➡
 
 This is a non-semantic scheduling message. The scheduling identifier (`➡️` by default) carries no meaning — it simply signals the next agent to check chat history and decide whether to speak.
 
+## Multi-message mode / shuffle mode
+
+- Human sends the configured start marker (default `↗️`) → channel enters multi-message mode.
+- While active, agents are forced to no-reply and the moderator sends only the configured prompt marker (default `⤵️`) after each additional human message.
+- Human sends the configured end marker (default `↙️`) → channel exits multi-message mode and normal scheduling resumes.
+- No separate moderator "entered/exited mode" confirmation message is sent; the markers themselves are the protocol.
+- The first moderator message after exit uses the normal scheduling handoff format: `<@NEXT_USER_ID>➡️`.
+- `/dirigent turn-shuffling`, `/dirigent turn-shuffling on`, and `/dirigent turn-shuffling off` control per-channel reshuffling between completed rounds.
+
 ## Slash command (Discord)
 
 ```
@@ -66,6 +78,9 @@ This is a non-semantic scheduling message. The scheduling identifier (`➡️` b
 /dirigent turn-status
 /dirigent turn-advance
 /dirigent turn-reset
+/dirigent turn-shuffling
+/dirigent turn-shuffling on
+/dirigent turn-shuffling off
 ```
 
 Debug logging: