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/bots-queue/process-bot-job.ts

@@ -27,6 +27,7 @@ import runBotJob from "./run-bot-job";
 import parseJobJson from "./parse-job-json";
 import nameBotSession from "./name-bot-session";
 import pushBotSession from "./push-bot-session";
+import { registerJobAbort, unregisterJobAbort } from "./job-abort-registry";
 import type { BotJobUpdateData } from "@/src/types";
 import type { BotJobContext, BotJobRunner } from "./types";
 
@@ -80,11 +81,6 @@ export default async function processBotJob({
      */
     const user_id = await grabJobUserId({ job }).catch(() => null);
 
-    const setFace = async (face: Omit<Parameters<typeof setBotFace>[0], "bot_id" | "user_id">) => {
-        if (!user_id) return;
-
-        await pushBotNotice({ bot_id, bot: await setBotFace({ bot_id, user_id, ...face }) });
-    };
     const controller = new AbortController();
     /**
      * The deadline is the one abort that is a failure, not a cancellation:
@@ -94,6 +90,25 @@ export default async function processBotJob({
     const timeout_message = `"${job.title || "The job"}" took too long and was stopped.`;
     let timed_out = false;
 
+    /**
+     * A stopped job never touches the face again: `stopBotJobs` already set
+     * it to idle, and a late `working` or `asleep` would push over that and
+     * leave a bot that shows work with nothing behind it.
+     */
+    const setFace = async (face: Omit<Parameters<typeof setBotFace>[0], "bot_id" | "user_id">) => {
+        if (!user_id || controller.signal.aborted) return;
+
+        await pushBotNotice({ bot_id, bot: await setBotFace({ bot_id, user_id, ...face }) });
+    };
+
+    /**
+     * Stopping the bot from the chat aborts the request this job is
+     * waiting on, here and now, rather than at the next heartbeat. The job
+     * is already failed in the queue, so an abort is a cancellation and its
+     * result is dropped (`controller.signal.aborted` below).
+     */
+    registerJobAbort({ job_id, abort: () => controller.abort() });
+
     const update: BotJobContext["update"] = async (params) => {
         if (controller.signal.aborted) return false;
 
@@ -305,5 +320,6 @@ export default async function processBotJob({
         }
     } finally {
         clearInterval(heartbeat);
+        unregisterJobAbort({ job_id });
     }
 }