feat(guest): prune deleted bot from guest scope on removeBot

When a bot is deleted, prune its id from config.guestMode.bots (when an
array) and persist, mirroring the existing permissions.pruneBot(id)
member-access pruning. Thread CONFIG_PATH into BotManager so removeBot
can save the updated config.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/bot/manager.test.ts

@@ -0,0 +1,87 @@
+import { describe, it, expect, afterEach } from "vitest";
+import { join } from "node:path";
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { BotManager } from "./manager.js";
+import { createDatabase, type BotDatabase } from "../data/database.js";
+import { createPermissionStore } from "../data/permissions.js";
+import { getDefaultConfig, loadConfig, saveConfig, type BotConfig } from "../data/config.js";
+import type { Logger } from "../logger.js";
+import type { MusicProvider } from "../music/provider.js";
+import type { AvatarStore } from "../data/avatars.js";
+
+// removeBot only calls logger.info; provide the full shape it could touch.
+const stubLogger = {
+  info() {},
+  warn() {},
+  error() {},
+  debug() {},
+  child() {
+    return stubLogger;
+  },
+} as unknown as Logger;
+
+describe("BotManager.removeBot — guest scope pruning", () => {
+  const dirs: string[] = [];
+  let db: BotDatabase;
+
+  function makeTmpConfigPath(): string {
+    const dir = mkdtempSync(join(tmpdir(), "tsmusicbot-manager-test-"));
+    dirs.push(dir);
+    return join(dir, "config.json");
+  }
+
+  function makeManager(config: BotConfig, configPath: string): BotManager {
+    db = createDatabase(":memory:");
+    const permissions = createPermissionStore(db.db);
+    saveConfig(configPath, config);
+    return new BotManager(
+      {} as unknown as MusicProvider,
+      {} as unknown as MusicProvider,
+      {} as unknown as MusicProvider,
+      db,
+      config,
+      stubLogger,
+      {} as unknown as AvatarStore,
+      permissions,
+      configPath
+    );
+  }
+
+  afterEach(() => {
+    try {
+      db?.close();
+    } catch {
+      /* ignore */
+    }
+    for (const d of dirs) {
+      rmSync(d, { recursive: true, force: true });
+    }
+    dirs.length = 0;
+  });
+
+  it("prunes a deleted bot from guestMode.bots (array) and persists", async () => {
+    const configPath = makeTmpConfigPath();
+    const config = getDefaultConfig();
+    config.guestMode.bots = ["botA", "botB"];
+    const manager = makeManager(config, configPath);
+
+    await manager.removeBot("botA");
+
+    expect(config.guestMode.bots).toEqual(["botB"]);
+    // Persisted file must also reflect the prune.
+    expect(loadConfig(configPath).guestMode.bots).toEqual(["botB"]);
+  });
+
+  it('leaves guestMode.bots === "all" unchanged (no crash, no change)', async () => {
+    const configPath = makeTmpConfigPath();
+    const config = getDefaultConfig();
+    config.guestMode.bots = "all";
+    const manager = makeManager(config, configPath);
+
+    await manager.removeBot("botA");
+
+    expect(config.guestMode.bots).toBe("all");
+    expect(loadConfig(configPath).guestMode.bots).toBe("all");
+  });
+});