Let a user stop a bot, and say the app is still alpha

The thinking row and the header menu both carry Stop while a bot has work
open for the user anywhere: every pending or processing job of that bot in
their conversations is failed as stopped, its task closed, a Stopped step
recorded and one closing message posted per session, so the thread stops
waiting and the bot goes idle. The handler running the job is aborted from
this process through a registry, so a job stuck waiting on a model stops at
once instead of on its next heartbeat, and a late face change after the
abort is dropped.

The release stage is now said in the app too: Settings > General reports
"Cobble v0.1.5 (alpha)" next to development, and the README and RELEASING.md
say what alpha means for installs.

src/pages/admin/bots/[bot_id]/(sections)/conversation.tsx

@@ -15,9 +15,15 @@ import { CrewBotsContext } from "../(data)/crew-bots-context";
 import { CrewWorkspacesContext } from "../(data)/crew-workspaces-context";
 import { BotMessageActionsContext } from "../(data)/message-actions-context";
 import { SpeakMessageContext } from "../(data)/speak-message-context";
+import {
+    StopBotContext,
+    type StopBotState,
+} from "../(data)/stop-bot-context";
 import reactToBotMessage from "../(functions)/react-to-bot-message";
+import botBusyState from "../(utils)/bot-busy-state";
 import dropSentMessage from "../(utils)/drop-sent-message";
 import useBotComputers from "../(hooks)/use-bot-computers";
+import useStopBot from "../(hooks)/use-stop-bot";
 import useTaskProgress from "../(hooks)/use-task-progress";
 import useReplyProgress from "../(hooks)/use-reply-progress";
 import useReplyCatchUp from "../(hooks)/use-reply-catch-up";
@@ -90,6 +96,10 @@ export default function Conversation() {
         workspace_id,
         computers: pageProps?.bot_computers || [],
     });
+    const stop_bot = useStopBot({
+        bot_id: bot?.id || 0,
+        workspace_id,
+    });
 
     const speak = useSpeakMessage({
         enabled: Boolean(pageProps?.bot_voice?.speech),
@@ -233,7 +243,26 @@ export default function Conversation() {
 
     if (!bot?.id || !live_bot) return null;
 
-    return (
+    /**
+     * What the stop control pulls the plug on, read the way the thinking
+     * row reads it: the same conditions, so the header's row is enabled
+     * exactly while the thread shows the bot at work.
+     */
+    const stop_state: StopBotState = {
+        ...stop_bot,
+        can_stop: botBusyState({
+            bot: live_bot,
+            awaiting_reply,
+            receiving: pending_messages.length > 0,
+            has_task: Boolean(progress.task_id),
+        }).stoppable,
+    };
+
+    /**
+     * The thread, kept intact so the stop control can wrap it without
+     * reindenting every provider.
+     */
+    const thread = (
         <CrewBotsContext.Provider value={bots}>
             <CrewWorkspacesContext.Provider value={workspaces}>
                 <BotComputersContext.Provider value={bot_computers}>
@@ -316,4 +345,10 @@ export default function Conversation() {
             </CrewWorkspacesContext.Provider>
         </CrewBotsContext.Provider>
     );
+
+    return (
+        <StopBotContext.Provider value={stop_state}>
+            {thread}
+        </StopBotContext.Provider>
+    );
 }