diff --git a/src/servers/api/chat/chat.ts b/src/servers/api/chat/chat.ts
index 18bc972f..3b78ea61 100644
--- a/src/servers/api/chat/chat.ts
+++ b/src/servers/api/chat/chat.ts
@@ -417,6 +417,16 @@ chatRouter.delete('/sessions/:id', async (ctx) => {
     return ctx.json({ ok: true });
   }
 
+  /*
+    Stop the harness BEFORE removing its file, and wait for it.
+
+    The `claude` CLI owns the transcript. Deleting it while a live session is still writing removes a file
+    that is written straight back, so the conversation reappears untitled on the next refresh — see
+    `killClaudeAndWait`. No live session means nothing to wait for, which is the ordinary case here.
+  */
+  const liveKey = sessionKeyForTranscript(id);
+  if (liveKey) await sidecar.killClaudeAndWait(liveKey, ctx.get('user').id);
+
   // `.length`, not truthiness: this returns the IDS it removed and an empty array is truthy in JavaScript,
   // so `if (removed)` would report a delete that found nothing as a success.
   const removed = deleteClaudeSession(who, cwd, id);
@@ -431,7 +441,6 @@ chatRouter.delete('/sessions/:id', async (ctx) => {
     `chat_session_events` is keyed on officer's session key. Undefined here is the normal case for an old
     conversation — no live session holds it, so nothing is keyed on a key to remove.
   */
-  const liveKey = sessionKeyForTranscript(id);
   await forgetChatSessions({ transcriptIds: removed, sessionKeys: liveKey ? [liveKey] : [] });
   return ctx.json({ ok: true });
 });
diff --git a/src/servers/api/command-hq/router.ts b/src/servers/api/command-hq/router.ts
index 1091c4a8..0f5622b4 100644
--- a/src/servers/api/command-hq/router.ts
+++ b/src/servers/api/command-hq/router.ts
@@ -6,7 +6,7 @@ import * as errors from '@@/custom-errors';
 import { resolveHomeDir } from '@@/user-home';
 import { getCommandersDir, toShellUsername } from '@@/data-path';
 import { forgetChatSessions, getChatEventsSince, ingestSpawnedChildren } from 'officerdb';
-import { killClaudeSession } from '@@/sidecar/claude/claude-manager';
+import * as sidecar from '@@/sidecar-registry';
 import { findSessionKeyByClaudeSession } from '@@/sidecar/claude/state';
 import { sessionKeyForTranscript } from '../chat/websocket';
 import {
@@ -560,7 +560,18 @@ commandHqRouter.delete('/commanders/:sessionId', async (ctx) => {
   // Same mapping problem as the briefing: the sidecar's map is not visible from here, so the platform's own
   // is asked first and the sidecar's is kept as a fallback for a session that predates this process.
   const sessionKey = sessionKeyForTranscript(sessionId) ?? findSessionKeyByClaudeSession(sessionId, user.id);
-  const sessionKilled = sessionKey ? killClaudeSession(sessionKey, user.id) : false;
+  /*
+    Across the socket, and AWAITED — both halves matter.
+
+    `killClaudeSession` from `claude-manager` was called directly here, and it could only ever return false:
+    the session map lives in the `officer-claude-code` process and this route runs in `officer`, so it was
+    reading an empty map in the wrong process. The kill silently never happened.
+
+    Awaited because the next thing this route does is delete the transcript, and the `claude` CLI owns that
+    file. Deleting it while the CLI is still unwinding removes a file that is written straight back — which
+    is exactly how a deleted commander came back as an untitled ordinary chat.
+  */
+  const sessionKilled = sessionKey ? await sidecar.killClaudeAndWait(sessionKey, user.id) : false;
   const stopped = stopCommanderProcesses(who.email, sessionId);
 
   // 2. Everything it spawned. Best-effort per child: one transcript that has already been cleaned up must
diff --git a/src/servers/sidecar-registry.ts b/src/servers/sidecar-registry.ts
index 6b8e0491..05833590 100644
--- a/src/servers/sidecar-registry.ts
+++ b/src/servers/sidecar-registry.ts
@@ -330,6 +330,26 @@ export function killClaude(sessionKey: string, userId: number): void {
   sendFire('claude', { type: 'claude:kill', id: nextId(), sessionKey, userId });
 }
 
+/**
+ * Kill a session and wait for the agent to confirm its child process is gone.
+ *
+ * For callers that then delete the session's FILES. The transcript belongs to the `claude` CLI, not to
+ * officer, so removing it while the CLI is still unwinding deletes a file that is written straight back —
+ * which resurrects a conversation the user deleted, as an untitled ordinary chat that nothing filters out.
+ *
+ * Never fatal: a sidecar that is down or slow must not block a delete. The caller proceeds and accepts the
+ * race it was already running, which is no worse than before this existed.
+ */
+export async function killClaudeAndWait(sessionKey: string, userId: number): Promise<boolean> {
+  try {
+    const sc = await waitForHandler('claude');
+    const res = await sendCommandToSidecar(sc, { type: 'claude:kill', id: nextId(), sessionKey, userId });
+    return res.type === 'claude:killed';
+  } catch {
+    return false;
+  }
+}
+
 // Interrupt the current turn but keep the persistent session warm (the "stop" button).
 export function interruptClaude(sessionKey: string, userId: number): void {
   sendFire('claude', { type: 'claude:interrupt', id: nextId(), sessionKey, userId });
diff --git a/src/servers/sidecar/claude/claude-manager.ts b/src/servers/sidecar/claude/claude-manager.ts
index 5b1824c8..a7158c8e 100644
--- a/src/servers/sidecar/claude/claude-manager.ts
+++ b/src/servers/sidecar/claude/claude-manager.ts
@@ -247,6 +247,18 @@ type PersistentSession = {
   interrupted: boolean;
   /** What we passed as `--resume`, so a failure can name it and decide whether it was to blame. */
   resumeId?: string;
+  /**
+   * Resolves when this session's child process is actually gone.
+   *
+   * Killing is not the same as being dead, and the difference is visible on disk: `abort()` returns at once
+   * while the `claude` CLI keeps writing for as long as it takes to unwind. Officer does not own the
+   * transcript — the CLI does — so a delete that races this window removes the file and the CLI writes it
+   * straight back, resurrecting a conversation the user deleted. Anything that deletes a session's FILES
+   * has to await this first.
+   */
+  exited: Promise<void>;
+  /** Called by the exit hook. Resolving twice is a no-op, which is what makes the double-fire safe. */
+  markExited: () => void;
   /**
    * The model this session is currently answering as, `harness/tier`.
    *
@@ -362,6 +374,10 @@ function spawnClaudeAsOwner({ command, args, cwd, env, signal }: SpawnOptions):
  * transcript by id.
  */
 function dropDeadSession(session: PersistentSession, detail: string): void {
+  // Before the identity guard, and deliberately: this fires on the real process exit, and a waiter must be
+  // released even when a newer session has already taken this key. Otherwise a replaced session's waiter
+  // blocks until its timeout for a process that died on schedule.
+  session.markExited();
   // Identity, not key: a later turn may have already replaced this entry, and killing its session because
   // its predecessor's process exited would break the live conversation instead of a dead one.
   if (sessions.get(session.sessionKey) !== session) return;
@@ -562,7 +578,13 @@ function createSession(
     interrupted: false,
     stderrTail: '',
     sawOutput: false,
+    // Assigned immediately below — the resolver has to escape the executor before the object is usable.
+    exited: undefined as unknown as Promise<void>,
+    markExited: () => {},
   };
+  session.exited = new Promise<void>((resolve) => {
+    session.markExited = resolve;
+  });
 
   // Strip the nested-session guard vars so the SDK can spawn `claude` (mirrors the old spawn env clean).
   const cleanEnv = envWithoutParentSession();
@@ -1236,6 +1258,33 @@ export async function interruptClaudeSession(sessionKey: string, userId: number)
 }
 
 /** Fully tear the session down (the "disconnect" action / idle GC): abort the query + close input. */
+/**
+ * Kill a session and wait for its child process to actually be gone.
+ *
+ * The bounded wait is the point. `killClaudeSession` returns as soon as it has aborted, which is before the
+ * `claude` CLI has finished writing — and the CLI, not officer, owns the transcript file. A caller that
+ * deletes files has to await this or it deletes them out from under a process still writing them.
+ *
+ * The timeout resolves rather than throws: a child that will not die within the window is a worse problem
+ * than a stale transcript, and blocking a user's delete on it forever helps nobody. The caller gets `false`
+ * and can say so.
+ */
+export async function killClaudeSessionAndWait(sessionKey: string, userId: number, timeoutMs = 5000): Promise<boolean> {
+  const session = ownedSession(sessionKey, userId);
+  if (!session) return false;
+  const { exited } = session;
+  killClaudeSession(sessionKey, userId);
+  let timer: ReturnType<typeof setTimeout> | undefined;
+  const timedOut = await Promise.race([
+    exited.then(() => false),
+    new Promise<boolean>((resolve) => {
+      timer = setTimeout(() => resolve(true), timeoutMs);
+    }),
+  ]);
+  if (timer) clearTimeout(timer);
+  return !timedOut;
+}
+
 export function killClaudeSession(sessionKey: string, userId: number): boolean {
   const session = ownedSession(sessionKey, userId);
   if (!session) return false;
diff --git a/src/servers/sidecar/claude/user-instance.ts b/src/servers/sidecar/claude/user-instance.ts
index 96881020..16458cea 100644
--- a/src/servers/sidecar/claude/user-instance.ts
+++ b/src/servers/sidecar/claude/user-instance.ts
@@ -294,11 +294,20 @@ async function handleCommand(cmd: SidecarCommand, reply: ReplyFn) {
       break;
     }
 
-    case 'claude:kill':
-      claudeManager.killClaudeSession(cmd.sessionKey, cmd.userId);
+    case 'claude:kill': {
+      /*
+        Reply only once the child is actually gone.
+      
+        The caller deleting a session's transcript has to know the CLI has stopped writing it, and this
+        reply is the only signal it can get — officer's side of the socket has no view of the process.
+        Bounded inside `killClaudeSessionAndWait`, so a child that will not die delays this by seconds
+        rather than hanging the caller's request.
+      */
+      await claudeManager.killClaudeSessionAndWait(cmd.sessionKey, cmd.userId);
       sessionLog.drop(cmd.sessionKey);
       reply({ type: 'claude:killed', id: cmd.id });
       break;
+    }
 
     case 'claude:interrupt':
       await claudeManager.interruptClaudeSession(cmd.sessionKey, cmd.userId);