diff --git a/.agents/skills/conversation-done/SKILL.md b/.agents/skills/conversation-done/SKILL.md
new file mode 100644
index 0000000000..11a5b21309
--- /dev/null
+++ b/.agents/skills/conversation-done/SKILL.md
@@ -0,0 +1,95 @@
+---
+name: conversation-done
+description: >-
+  Clean up files and resources that aren't part of the agent conversation
+  (e.g. Bazel output base, Git worktree, local/remote branches)
+---
+
+# Conversation Done Skill
+
+Cleans up external workspace resources created during agent workflows while
+preserving agent conversation data, chat history, and brain transcripts.
+
+## Overview
+
+When agents work on tasks, several external resources outside the agent
+conversation directory (`~/.gemini/jetski/brain/`) are created:
+
+1. **Bazel Output Base(s)**: Intermediate build artifacts, execroot trees,
+   and running Bazel server and persistent worker processes (consuming tens of
+   gigabytes of disk and substantial RAM).
+2. **Git Worktree**: The checked-out directory on disk.
+3. **Local Git Branch**: The feature branch associated with the worktree.
+4. **Remote Git Branch**: The feature branch pushed to the user's fork
+   (e.g., `origin`).
+
+This skill safely shuts down active build processes and reclaims these
+resources without removing the conversation transcript or chat history.
+
+## Script Location
+
+The cleanup script is located at:
+`./.agents/skills/conversation-done/scripts/cleanup.py`
+
+## Usage
+
+### 1. Clean Up Current Workspace
+
+When invoked from within the agent's worktree:
+
+```bash
+# Preview what would be removed:
+./.agents/skills/conversation-done/scripts/cleanup.py --dry-run
+
+# Clean up resources (interactive confirmation if TTY):
+./.agents/skills/conversation-done/scripts/cleanup.py
+
+# Force cleanup non-interactively (ideal for agents/scripts):
+./.agents/skills/conversation-done/scripts/cleanup.py --force
+```
+
+### 2. Clean Up by Worktree Path or Branches
+
+```bash
+# By worktree path:
+./.agents/skills/conversation-done/scripts/cleanup.py \
+  --worktree /path/to/worktree --force
+
+# By branch name:
+./.agents/skills/conversation-done/scripts/cleanup.py \
+  --branches my-feature-branch --force
+
+# By multiple branches:
+./.agents/skills/conversation-done/scripts/cleanup.py \
+  --branches branch-one branch-two --force
+```
+
+### 3. Inspect Active Resources
+
+List all worktrees, branches, and Bazel output bases:
+
+```bash
+./.agents/skills/conversation-done/scripts/cleanup.py --list
+```
+
+## Selective Cleanup Flags
+
+Fine-tune what gets cleaned up using selective leave flags:
+
+* `--leave-bazel-output-base`: Leave Bazel output bases and build caches
+  intact.
+* `--leave-worktree`: Leave Git worktree directory on disk.
+* `--leave-branch`: Keep local Git branch.
+* `--leave-remote`: Do not delete branch from remote fork.
+* `--remote <name>`: Override remote destination (default: `pushRemote` or
+  `origin`).
+
+## Safety Guarantees
+
+* **Main Repository Protection**: Never removes the primary Git repository
+  worktree.
+* **Protected Branches**: Never deletes `main`, `master`, `release/*`, or
+  `HEAD`.
+* **Upstream Remote Protection**: Never deletes branches on `upstream`.
+* **No Expunge Rule**: Never runs `bazel clean --expunge`; shuts down servers
+  gracefully and deletes the specific output base directory directly.
diff --git a/.agents/skills/conversation-done/scripts/cleanup.py b/.agents/skills/conversation-done/scripts/cleanup.py
new file mode 100755
index 0000000000..24d13a3cd2
--- /dev/null
+++ b/.agents/skills/conversation-done/scripts/cleanup.py
@@ -0,0 +1,781 @@
+#!/usr/bin/env python3
+"""Cleans up workspace resources created for an agent conversation.
+
+This script cleans up files and resources that are external to the agent
+conversation itself (such as Bazel output bases, Git worktrees, and local or
+remote Git branches), while leaving the conversation history, transcripts,
+and brain state intact.
+
+Usage examples:
+  # Clean up current worktree and its associated resources:
+  cleanup.py
+
+  # Preview what would be cleaned up without making changes:
+  cleanup.py --dry-run
+
+  # Clean up a specific worktree by path:
+  cleanup.py --worktree /path/to/worktree
+
+  # Clean up resources for specific branches:
+  cleanup.py --branches my-feature-branch
+
+  # Clean up resources for multiple branches:
+  cleanup.py --branches branch-one branch-two
+
+  # List worktrees and their associated resources:
+  cleanup.py --list
+"""
+
+from __future__ import annotations
+
+import argparse
+import asyncio
+import dataclasses
+import glob
+import os
+import shutil
+import signal
+import stat
+import subprocess
+import sys
+
+PROTECTED_BRANCHES = frozenset({"main", "master", "HEAD"})
+PROTECTED_REMOTES = frozenset({"upstream"})
+
+
+@dataclasses.dataclass
+class WorktreeInfo:
+    """Information about a Git worktree."""
+
+    path: str
+    head: str
+    branch: str | None
+    is_main: bool
+
+
+@dataclasses.dataclass
+class CleanupTarget:
+    """Target resources identified for cleanup."""
+
+    worktree_path: str | None = None
+    branch: str | None = None
+    remote: str | None = None
+    remote_branch_exists: bool = False
+    bazel_output_bases: list[str] = dataclasses.field(default_factory=list)
+    is_main_worktree: bool = False
+
+
+def log(msg: str) -> None:
+    """Prints an informational message."""
+    print(msg, flush=True)
+
+
+def log_warn(msg: str) -> None:
+    """Prints a warning message to stderr."""
+    print(f"Warning: {msg}", file=sys.stderr, flush=True)
+
+
+def log_error(msg: str) -> None:
+    """Prints an error message to stderr."""
+    print(f"Error: {msg}", file=sys.stderr, flush=True)
+
+
+async def run_command(
+    cmd: list[str],
+    cwd: str | None = None,
+    capture_output: bool = True,
+    timeout: float | None = None,
+) -> subprocess.CompletedProcess[str]:
+    """Executes a subprocess command asynchronously and safely."""
+    stdout_pipe = asyncio.subprocess.PIPE if capture_output else None
+    stderr_pipe = asyncio.subprocess.PIPE if capture_output else None
+    try:
+        proc = await asyncio.create_subprocess_exec(
+            *cmd,
+            cwd=cwd,
+            stdout=stdout_pipe,
+            stderr=stderr_pipe,
+        )
+        try:
+            stdout_b, stderr_b = await asyncio.wait_for(
+                proc.communicate(), timeout=timeout
+            )
+        except asyncio.TimeoutError:
+            try:
+                proc.kill()
+                await proc.wait()
+            except OSError:
+                pass
+            return subprocess.CompletedProcess(
+                args=cmd,
+                returncode=1,
+                stdout="",
+                stderr=f"Command timed out after {timeout} seconds",
+            )
+        stdout = stdout_b.decode("utf-8", errors="replace") if stdout_b else ""
+        stderr = stderr_b.decode("utf-8", errors="replace") if stderr_b else ""
+        return subprocess.CompletedProcess(
+            args=cmd,
+            returncode=proc.returncode if proc.returncode is not None else 0,
+            stdout=stdout,
+            stderr=stderr,
+        )
+    except (FileNotFoundError, OSError) as exc:
+        return subprocess.CompletedProcess(
+            args=cmd,
+            returncode=1,
+            stdout="",
+            stderr=str(exc),
+        )
+
+
+async def get_main_repo(cwd: str | None = None) -> str:
+    """Finds the root directory of the primary Git repository."""
+    res = await run_command(["git", "rev-parse", "--git-common-dir"], cwd=cwd)
+    if res.returncode == 0 and res.stdout.strip():
+        git_common = os.path.abspath(res.stdout.strip())
+        if os.path.basename(git_common) == ".git":
+            return os.path.dirname(git_common)
+        return git_common
+
+    res = await run_command(["git", "rev-parse", "--show-toplevel"], cwd=cwd)
+    if res.returncode == 0 and res.stdout.strip():
+        return os.path.abspath(res.stdout.strip())
+
+    raise RuntimeError("Not inside a Git repository.")
+
+
+async def get_current_worktree(cwd: str | None = None) -> str | None:
+    """Returns the top-level directory of the current worktree, if any."""
+    res = await run_command(["git", "rev-parse", "--show-toplevel"], cwd=cwd)
+    if res.returncode == 0 and res.stdout.strip():
+        return os.path.abspath(res.stdout.strip())
+    return None
+
+
+async def get_worktrees(main_repo: str) -> list[WorktreeInfo]:
+    """Returns all Git worktrees registered in the repository."""
+    res = await run_command(["git", "-C", main_repo, "worktree", "list", "--porcelain"])
+    if res.returncode != 0:
+        log_error(f"Failed to list Git worktrees: {res.stderr.strip()}")
+        return []
+
+    worktrees: list[WorktreeInfo] = []
+    current_wt: str | None = None
+    current_head = ""
+    current_branch: str | None = None
+
+    for line in res.stdout.splitlines():
+        line = line.strip()
+        if line.startswith("worktree "):
+            if current_wt:
+                worktrees.append(
+                    WorktreeInfo(
+                        path=current_wt,
+                        head=current_head,
+                        branch=current_branch,
+                        is_main=len(worktrees) == 0,
+                    )
+                )
+            current_wt = line.split("worktree ", 1)[1].strip()
+            current_head = ""
+            current_branch = None
+        elif line.startswith("HEAD "):
+            current_head = line.split("HEAD ", 1)[1].strip()
+        elif line.startswith("branch refs/heads/"):
+            current_branch = line.split("branch refs/heads/", 1)[1].strip()
+
+    if current_wt:
+        worktrees.append(
+            WorktreeInfo(
+                path=current_wt,
+                head=current_head,
+                branch=current_branch,
+                is_main=len(worktrees) == 0,
+            )
+        )
+
+    return worktrees
+
+
+def is_protected_branch(branch: str | None) -> bool:
+    """Checks if a branch is protected from deletion."""
+    if not branch:
+        return True
+    if branch in PROTECTED_BRANCHES:
+        return True
+    if branch.startswith("release/") or branch.startswith("release-"):
+        return True
+    return False
+
+
+async def get_push_remote_for_branch(main_repo: str, branch: str) -> str:
+    """Determines the push remote for a branch, defaulting to 'origin'."""
+    res = await run_command(
+        ["git", "-C", main_repo, "config", f"branch.{branch}.pushRemote"]
+    )
+    remote = res.stdout.strip()
+    if remote:
+        return remote
+
+    res = await run_command(
+        ["git", "-C", main_repo, "config", f"branch.{branch}.remote"]
+    )
+    remote = res.stdout.strip()
+    if remote and remote not in PROTECTED_REMOTES:
+        return remote
+
+    return "origin"
+
+
+async def remote_branch_exists(main_repo: str, remote: str, branch: str) -> bool:
+    """Checks whether a branch exists on the specified remote."""
+    if remote in PROTECTED_REMOTES or is_protected_branch(branch):
+        return False
+    res = await run_command(
+        ["git", "-C", main_repo, "ls-remote", "--heads", remote, branch],
+        timeout=10,
+    )
+    return res.returncode == 0 and bool(res.stdout.strip())
+
+
+def find_bazel_output_bases(target_worktree: str) -> list[str]:
+    """Finds all Bazel output bases associated with a worktree path."""
+    target_worktree = os.path.realpath(target_worktree)
+    output_bases: list[str] = []
+
+    user_cache = os.path.expanduser("~/.cache/bazel")
+    if not os.path.isdir(user_cache):
+        return output_bases
+
+    for user_dir in glob.glob(os.path.join(user_cache, "_bazel_*")):
+        if not os.path.isdir(user_dir):
+            continue
+        for ob in glob.glob(os.path.join(user_dir, "*")):
+            if not os.path.isdir(ob) or os.path.basename(ob) in ("cache", "install"):
+                continue
+            dnbh = os.path.join(ob, "DO_NOT_BUILD_HERE")
+            if os.path.isfile(dnbh):
+                try:
+                    with open(dnbh, "r", encoding="utf-8") as f:
+                        ws = os.path.realpath(f.read().strip())
+                    if ws == target_worktree or ws.startswith(target_worktree + os.sep):
+                        output_bases.append(ob)
+                except OSError:
+                    pass
+
+    return sorted(list(set(output_bases)))
+
+
+async def get_path_size_human(path: str) -> str:
+    """Returns human-readable size of a directory path."""
+    if not os.path.exists(path):
+        return "0 B"
+    res = await run_command(["du", "-sk", path], timeout=5)
+    if res.returncode == 0 and res.stdout.strip():
+        try:
+            kb = int(res.stdout.split()[0])
+            if kb < 1024:
+                return f"{kb} KB"
+            mb = kb / 1024.0
+            if mb < 1024:
+                return f"{mb:.1f} MB"
+            gb = mb / 1024.0
+            return f"{gb:.2f} GB"
+        except (ValueError, IndexError):
+            pass
+    return "unknown size"
+
+
+async def shutdown_and_remove_bazel_output_base(
+    output_base: str, dry_run: bool = False
+) -> bool:
+    """Cleanly shuts down the Bazel server and removes the output base directory."""
+    if dry_run:
+        log(
+            f"  [Dry Run] Would shutdown Bazel server and delete output base: {output_base}"
+        )
+        return True
+
+    log(f"  Shutting down Bazel server for output base: {output_base}")
+    # 1. Graceful shutdown command
+    await run_command(
+        ["bazel", f"--output_base={output_base}", "shutdown"],
+        timeout=10,
+    )
+
+    # 2. Check for running server process from server.pid.txt
+    server_pid_file = os.path.join(output_base, "server", "server.pid.txt")
+    if os.path.isfile(server_pid_file):
+        try:
+            with open(server_pid_file, "r", encoding="utf-8") as f:
+                pid = int(f.read().strip())
+            os.kill(pid, 0)
+            log(f"  Terminating lingering Bazel server process (PID: {pid})...")
+            os.kill(pid, signal.SIGTERM)
+            await asyncio.sleep(0.5)
+            try:
+                os.kill(pid, signal.SIGKILL)
+            except OSError:
+                pass
+        except (ValueError, OSError):
+            pass
+
+    # 3. Terminate any persistent workers or subprocesses tied to this output base
+    terminate_processes_under_path(output_base)
+
+    # 4. Remove output base directory (NEVER run bazel clean --expunge per rules)
+    log(f"  Removing Bazel output base directory: {output_base}")
+    return await remove_directory_safely(output_base)
+
+
+def terminate_processes_under_path(path: str) -> None:
+    """Terminates active processes running binaries or workers inside path."""
+    current_pid = os.getpid()
+    if not os.path.isdir("/proc"):
+        return
+
+    real_path = os.path.realpath(path)
+    for entry in os.listdir("/proc"):
+        if not entry.isdigit():
+            continue
+        pid = int(entry)
+        if pid == current_pid or pid == 1:
+            continue
+        try:
+            exe = os.path.realpath(f"/proc/{pid}/exe")
+            if exe.startswith(real_path + os.sep):
+                os.kill(pid, signal.SIGTERM)
+                continue
+            with open(f"/proc/{pid}/cmdline", "rb") as f:
+                cmdline = f.read().decode("utf-8", errors="ignore")
+            if real_path in cmdline:
+                os.kill(pid, signal.SIGTERM)
+        except (OSError, FileNotFoundError):
+            continue
+
+
+async def remove_directory_safely(path: str) -> bool:
+    """Recursively removes a directory tree, making read-only files writable."""
+    if not os.path.exists(path) and not os.path.islink(path):
+        return True
+
+    res = await run_command(["rm", "-rf", path])
+    if res.returncode == 0 and not os.path.exists(path):
+        return True
+
+    def _sync_rmtree():
+        def _make_writable_and_retry(func, fpath, unused_exc_info):
+            try:
+                os.chmod(fpath, stat.S_IWRITE | stat.S_IWUSR | stat.S_IRUSR)
+                func(fpath)
+            except OSError:
+                pass
+
+        try:
+            shutil.rmtree(path, onerror=_make_writable_and_retry)
+        except Exception as exc:
+            log_warn(f"Failed to completely remove {path}: {exc}")
+
+    await asyncio.to_thread(_sync_rmtree)
+    return not os.path.exists(path)
+
+
+async def remove_git_worktree(
+    main_repo: str, worktree_path: str, dry_run: bool = False
+) -> bool:
+    """Removes a Git worktree safely."""
+    real_wt = os.path.realpath(worktree_path)
+    real_main = os.path.realpath(main_repo)
+
+    if real_wt == real_main:
+        log_error(f"Cannot remove main repository worktree: {worktree_path}")
+        return False
+
+    if dry_run:
+        log(f"  [Dry Run] Would remove Git worktree: {worktree_path}")
+        return True
+
+    # If current working directory is inside worktree, cd to main repo
+    try:
+        cwd = os.path.realpath(os.getcwd())
+        if cwd == real_wt or cwd.startswith(real_wt + os.sep):
+            os.chdir(real_main)
+    except OSError:
+        os.chdir(real_main)
+
+    log(f"  Removing Git worktree: {worktree_path}")
+    res = await run_command(
+        ["git", "-C", real_main, "worktree", "remove", "--force", real_wt]
+    )
+    if res.returncode != 0:
+        log_warn(
+            f"git worktree remove failed ({res.stderr.strip()}), removing directly..."
+        )
+        await remove_directory_safely(real_wt)
+        await run_command(["git", "-C", real_main, "worktree", "prune"])
+
+    return not os.path.exists(real_wt)
+
+
+async def delete_local_branch(
+    main_repo: str, branch: str, dry_run: bool = False
+) -> tuple[bool, str]:
+    """Deletes a local Git branch."""
+    if is_protected_branch(branch):
+        return False, f"Branch '{branch}' is protected and will not be deleted."
+
+    if dry_run:
+        return True, f"[Dry Run] Would delete local branch '{branch}'."
+
+    # Verify branch is not checked out in another worktree
+    worktrees = await get_worktrees(main_repo)
+    for wt in worktrees:
+        if wt.branch == branch and os.path.exists(wt.path):
+            return (
+                False,
+                f"Branch '{branch}' is still checked out in active worktree: {wt.path}",
+            )
+
+    res = await run_command(["git", "-C", main_repo, "branch", "-D", branch])
+    if res.returncode == 0:
+        return True, f"Deleted local branch '{branch}'."
+    return False, f"Failed to delete local branch '{branch}': {res.stderr.strip()}"
+
+
+async def delete_remote_branch(
+    main_repo: str,
+    branch: str,
+    remote: str,
+    dry_run: bool = False,
+) -> tuple[bool, str]:
+    """Deletes a branch on the remote fork."""
+    if is_protected_branch(branch):
+        return False, f"Branch '{branch}' is protected and will not be deleted."
+
+    if remote in PROTECTED_REMOTES:
+        return (
+            False,
+            f"Remote '{remote}' is protected (canonical upstream). Branch will not be deleted.",
+        )
+
+    exists = await remote_branch_exists(main_repo, remote, branch)
+    if not exists:
+        return True, f"Remote branch '{branch}' does not exist on '{remote}'."
+
+    if dry_run:
+        return (
+            True,
+            f"[Dry Run] Would delete remote branch '{branch}' on remote '{remote}'.",
+        )
+
+    res = await run_command(
+        ["git", "-C", main_repo, "push", remote, "--delete", branch],
+        timeout=30,
+    )
+    if res.returncode == 0:
+        return True, f"Deleted remote branch '{branch}' from '{remote}'."
+    return (
+        False,
+        f"Failed to delete remote branch '{branch}' on '{remote}': {res.stderr.strip()}",
+    )
+
+
+async def build_cleanup_target(
+    main_repo: str,
+    worktree_path: str | None,
+    branch: str | None,
+    remote: str | None = None,
+) -> CleanupTarget:
+    """Assembles all resources associated with a target worktree/branch."""
+    target = CleanupTarget(
+        worktree_path=worktree_path,
+        branch=branch,
+        remote=remote,
+    )
+
+    if worktree_path:
+        real_wt = os.path.realpath(worktree_path)
+        real_main = os.path.realpath(main_repo)
+        target.is_main_worktree = real_wt == real_main
+        target.bazel_output_bases = find_bazel_output_bases(worktree_path)
+
+    if branch:
+        if not target.remote:
+            target.remote = await get_push_remote_for_branch(main_repo, branch)
+        if target.remote and target.remote not in PROTECTED_REMOTES:
+            target.remote_branch_exists = await remote_branch_exists(
+                main_repo, target.remote, branch
+            )
+
+    return target
+
+
+async def execute_cleanup_target(
+    main_repo: str,
+    target: CleanupTarget,
+    leave_bazel_output_base: bool = False,
+    leave_worktree: bool = False,
+    leave_branch: bool = False,
+    leave_remote: bool = False,
+    dry_run: bool = False,
+) -> None:
+    """Executes cleanup on a single target."""
+    log(f"\nCleaning up target resources for: {target.worktree_path or target.branch}")
+
+    if target.is_main_worktree:
+        log_error(
+            "Target is the main repository! Refusing to clean up main repository."
+        )
+        return
+
+    # 1. Clean up Bazel output bases
+    if not leave_bazel_output_base and target.bazel_output_bases:
+        log("1. Cleaning up Bazel output bases:")
+        for ob in target.bazel_output_bases:
+            size_str = await get_path_size_human(ob)
+            log(f"  - Output base: {ob} ({size_str})")
+            await shutdown_and_remove_bazel_output_base(ob, dry_run=dry_run)
+    elif leave_bazel_output_base:
+        log("1. Leaving Bazel output base intact.")
+    else:
+        log("1. No associated Bazel output bases found.")
+
+    # 2. Clean up Git worktree
+    if not leave_worktree and target.worktree_path:
+        log("2. Cleaning up Git worktree:")
+        await remove_git_worktree(main_repo, target.worktree_path, dry_run=dry_run)
+    elif leave_worktree:
+        log("2. Leaving Git worktree directory on disk.")
+    else:
+        log("2. No worktree directory to remove.")
+
+    # 3. Clean up local Git branch
+    if not leave_branch and target.branch:
+        log(f"3. Cleaning up local branch '{target.branch}':")
+        success, msg = await delete_local_branch(
+            main_repo, target.branch, dry_run=dry_run
+        )
+        if success:
+            log(f"  {msg}")
+        else:
+            log_warn(f"  {msg}")
+    elif leave_branch:
+        log("3. Leaving local branch intact.")
+    else:
+        log("3. No local branch specified.")
+
+    # 4. Clean up remote Git branch
+    if (
+        not leave_remote
+        and target.branch
+        and target.remote
+        and target.remote_branch_exists
+    ):
+        log(f"4. Cleaning up remote branch '{target.branch}' on '{target.remote}':")
+        success, msg = await delete_remote_branch(
+            main_repo, target.branch, target.remote, dry_run=dry_run
+        )
+        if success:
+            log(f"  {msg}")
+        else:
+            log_warn(f"  {msg}")
+    elif leave_remote:
+        log("4. Leaving remote branch intact.")
+    elif target.branch and target.remote:
+        log(f"4. Remote branch '{target.branch}' not present on '{target.remote}'.")
+
+
+async def list_resources(main_repo: str) -> None:
+    """Lists all worktrees and their associated resources."""
+    worktrees = await get_worktrees(main_repo)
+    log(f"Found {len(worktrees)} Git worktrees in {main_repo}:\n")
+    for wt in worktrees:
+        kind = " [MAIN REPO]" if wt.is_main else ""
+        branch_str = f" (branch: {wt.branch})" if wt.branch else " (detached HEAD)"
+        log(f"* {wt.path}{kind}{branch_str}")
+        obs = find_bazel_output_bases(wt.path)
+        if obs:
+            for ob in obs:
+                size_str = await get_path_size_human(ob)
+                log(f"    - Bazel output base: {ob} ({size_str})")
+        else:
+            log("    - No Bazel output base found.")
+
+
+def parse_args() -> argparse.Namespace:
+    """Parses command-line arguments."""
+    parser = argparse.ArgumentParser(
+        description="Clean up agent workspace resources (Bazel output base, worktree, branches)."
+    )
+    parser.add_argument(
+        "--worktree",
+        type=str,
+        default=None,
+        help="Path to the Git worktree to clean up.",
+    )
+    parser.add_argument(
+        "--branches",
+        nargs="+",
+        default=[],
+        help="One or more branch names to clean up.",
+    )
+    parser.add_argument(
+        "--remote",
+        type=str,
+        default=None,
+        help="Remote name for remote branch deletion (default: pushRemote or origin).",
+    )
+    parser.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="Preview resources to delete without making changes.",
+    )
+    parser.add_argument(
+        "-f",
+        "--force",
+        action="store_true",
+        help="Proceed with cleanup without interactive confirmation.",
+    )
+    parser.add_argument(
+        "--list",
+        action="store_true",
+        help="List worktrees, branches, and associated Bazel output bases.",
+    )
+    parser.add_argument(
+        "--leave-bazel-output-base",
+        action="store_true",
+        help="Leave Bazel output bases and build caches intact.",
+    )
+    parser.add_argument(
+        "--leave-worktree",
+        action="store_true",
+        help="Leave Git worktree directory on disk.",
+    )
+    parser.add_argument(
+        "--leave-branch",
+        action="store_true",
+        help="Keep local Git branch.",
+    )
+    parser.add_argument(
+        "--leave-remote",
+        action="store_true",
+        help="Do not delete branch from remote fork.",
+    )
+    return parser.parse_args()
+
+
+async def async_main() -> None:
+    """Async CLI entrypoint."""
+    args = parse_args()
+    main_repo = await get_main_repo()
+
+    if args.list:
+        await list_resources(main_repo)
+        return
+
+    worktrees = await get_worktrees(main_repo)
+    targets: list[CleanupTarget] = []
+
+    # If branches were explicitly provided
+    if args.branches:
+        for branch in args.branches:
+            wt_path = None
+            for wt in worktrees:
+                if wt.branch == branch:
+                    wt_path = wt.path
+                    break
+            target = await build_cleanup_target(
+                main_repo, wt_path, branch, remote=args.remote
+            )
+            targets.append(target)
+
+    # If worktree was explicitly provided
+    elif args.worktree:
+        real_target = os.path.realpath(args.worktree)
+        found_branch = None
+        for wt in worktrees:
+            if os.path.realpath(wt.path) == real_target:
+                found_branch = wt.branch
+                break
+        target = await build_cleanup_target(
+            main_repo, args.worktree, found_branch, remote=args.remote
+        )
+        targets.append(target)
+
+    # Otherwise default to current worktree
+    else:
+        curr_wt = await get_current_worktree()
+        if not curr_wt:
+            log_error(
+                "Could not determine current worktree. "
+                "Specify --worktree or --branches."
+            )
+            sys.exit(1)
+
+        real_curr = os.path.realpath(curr_wt)
+        real_main = os.path.realpath(main_repo)
+        if real_curr == real_main:
+            log_error(
+                "Currently inside the main repository. Refusing to clean up main repository.\n"
+                "Specify --worktree or --branches."
+            )
+            sys.exit(1)
+
+        found_branch = None
+        for wt in worktrees:
+            if os.path.realpath(wt.path) == real_curr:
+                found_branch = wt.branch
+                break
+
+        target = await build_cleanup_target(
+            main_repo, curr_wt, found_branch, remote=args.remote
+        )
+        targets.append(target)
+
+    if not targets:
+        log_error("No valid targets identified for cleanup.")
+        sys.exit(1)
+
+    # Show preview
+    for target in targets:
+        log("\nIdentified resources for cleanup:")
+        if target.worktree_path:
+            log(f"  Worktree directory: {target.worktree_path}")
+        if target.bazel_output_bases:
+            for ob in target.bazel_output_bases:
+                size_str = await get_path_size_human(ob)
+                log(f"  Bazel output base:  {ob} ({size_str})")
+        else:
+            log("  Bazel output base:  None found")
+        if target.branch:
+            log(f"  Local branch:       {target.branch}")
+        if target.remote and target.remote_branch_exists:
+            log(f"  Remote branch:      {target.remote}/{target.branch}")
+
+    if not args.force and not args.dry_run and sys.stdin.isatty():
+        confirm = input("\nProceed with cleanup? [y/N]: ").strip()
+        if confirm.lower() not in ("y", "yes"):
+            log("Aborted.")
+            return
+
+    for target in targets:
+        await execute_cleanup_target(
+            main_repo,
+            target,
+            leave_bazel_output_base=args.leave_bazel_output_base,
+            leave_worktree=args.leave_worktree,
+            leave_branch=args.leave_branch,
+            leave_remote=args.leave_remote,
+            dry_run=args.dry_run,
+        )
+    log("\nCleanup completed.")
+
+
+def main() -> None:
+    """Main CLI entrypoint."""
+    asyncio.run(async_main())
+
+
+if __name__ == "__main__":
+    main()
diff --git a/.agents/skills/conversation-done/scripts/cleanup_test.py b/.agents/skills/conversation-done/scripts/cleanup_test.py
new file mode 100644
index 0000000000..18a38b1ef3
--- /dev/null
+++ b/.agents/skills/conversation-done/scripts/cleanup_test.py
@@ -0,0 +1,153 @@
+#!/usr/bin/env python3
+"""Unit tests for the async cleanup script."""
+
+import os
+import subprocess
+import sys
+import tempfile
+import unittest
+from unittest import mock
+
+# Ensure scripts dir is in sys.path
+sys_path = os.path.dirname(os.path.abspath(__file__))
+if sys_path not in sys.path:
+    sys.path.insert(0, sys_path)
+
+import cleanup  # noqa: E402
+
+
+class CleanupScriptTest(unittest.IsolatedAsyncioTestCase):
+    """Tests for cleanup.py async logic and safety guards."""
+
+    def test_is_protected_branch(self):
+        """Verifies protected branches cannot be deleted."""
+        self.assertTrue(cleanup.is_protected_branch("main"))
+        self.assertTrue(cleanup.is_protected_branch("master"))
+        self.assertTrue(cleanup.is_protected_branch("HEAD"))
+        self.assertTrue(cleanup.is_protected_branch("release/1.0"))
+        self.assertTrue(cleanup.is_protected_branch("release/2026-08"))
+        self.assertTrue(cleanup.is_protected_branch("release-1.0"))
+        self.assertTrue(cleanup.is_protected_branch("release-2026-08"))
+        self.assertTrue(cleanup.is_protected_branch(None))
+        self.assertFalse(cleanup.is_protected_branch("feature/my-cool-branch"))
+        self.assertFalse(cleanup.is_protected_branch("bugfix-1234"))
+
+    async def test_worktrees_parsing(self):
+        """Verifies parsing git worktree list porcelain output."""
+        sample_output = """worktree /path/to/main/repo
+HEAD 03f212c3f3b590a7103d512650ce09818d30d218
+branch refs/heads/main
+
+worktree /path/to/worktrees/feat1
+HEAD f130aea7fa0eab7d558897ed0ad915a1057e065c
+branch refs/heads/feat1
+
+worktree /path/to/worktrees/detached
+HEAD 21e9bd5b3b069d4057abac69adf985b7907308f8
+detached
+"""
+        with mock.patch("cleanup.run_command") as mock_run:
+            mock_run.return_value = subprocess.CompletedProcess(
+                args=[], returncode=0, stdout=sample_output, stderr=""
+            )
+            worktrees = await cleanup.get_worktrees("/path/to/main/repo")
+
+        self.assertEqual(len(worktrees), 3)
+        self.assertEqual(worktrees[0].path, "/path/to/main/repo")
+        self.assertTrue(worktrees[0].is_main)
+        self.assertEqual(worktrees[0].branch, "main")
+
+        self.assertEqual(worktrees[1].path, "/path/to/worktrees/feat1")
+        self.assertFalse(worktrees[1].is_main)
+        self.assertEqual(worktrees[1].branch, "feat1")
+
+        self.assertEqual(worktrees[2].path, "/path/to/worktrees/detached")
+        self.assertFalse(worktrees[2].is_main)
+        self.assertIsNone(worktrees[2].branch)
+
+    def test_find_bazel_output_bases(self):
+        """Verifies finding Bazel output bases matching target workspace."""
+        with tempfile.TemporaryDirectory() as temp_dir:
+            user_dir = os.path.join(temp_dir, "_bazel_testuser")
+            os.makedirs(user_dir)
+
+            # Output base 1: matches main worktree
+            ob1 = os.path.join(user_dir, "hash1")
+            os.makedirs(ob1)
+            with open(os.path.join(ob1, "DO_NOT_BUILD_HERE"), "w") as f:
+                f.write("/home/user/worktrees/my_feature\n")
+
+            # Output base 2: matches nested integration workspace
+            ob2 = os.path.join(user_dir, "hash2")
+            os.makedirs(ob2)
+            with open(os.path.join(ob2, "DO_NOT_BUILD_HERE"), "w") as f:
+                f.write("/home/user/worktrees/my_feature/tests/integration/nested\n")
+
+            # Output base 3: unrelated workspace
+            ob3 = os.path.join(user_dir, "hash3")
+            os.makedirs(ob3)
+            with open(os.path.join(ob3, "DO_NOT_BUILD_HERE"), "w") as f:
+                f.write("/home/user/worktrees/different_feature\n")
+
+            with mock.patch("os.path.expanduser", return_value=temp_dir):
+                bases = cleanup.find_bazel_output_bases(
+                    "/home/user/worktrees/my_feature"
+                )
+
+            self.assertEqual(sorted(bases), sorted([ob1, ob2]))
+
+    async def test_main_repo_safety(self):
+        """Verifies refusal to remove main repository worktree."""
+        main_repo = "/repo/main"
+        target = cleanup.CleanupTarget(
+            worktree_path="/repo/main",
+            branch="main",
+            is_main_worktree=True,
+        )
+        with mock.patch("cleanup.remove_git_worktree") as mock_rm_wt, mock.patch(
+            "cleanup.log_error"
+        ) as mock_log_err:
+            await cleanup.execute_cleanup_target(main_repo, target)
+            mock_rm_wt.assert_not_called()
+            mock_log_err.assert_called_with(
+                "Target is the main repository! Refusing to clean up main repository."
+            )
+
+    async def test_protected_branch_safety(self):
+        """Verifies refusal to delete protected branch."""
+        success, msg = await cleanup.delete_local_branch("/repo/main", "main")
+        self.assertFalse(success)
+        self.assertIn("protected", msg)
+
+        success, msg = await cleanup.delete_remote_branch(
+            "/repo/main", "main", "origin"
+        )
+        self.assertFalse(success)
+        self.assertIn("protected", msg)
+
+    async def test_upstream_remote_safety(self):
+        """Verifies refusal to delete branch on upstream remote."""
+        success, msg = await cleanup.delete_remote_branch(
+            "/repo/main", "feature-x", "upstream"
+        )
+        self.assertFalse(success)
+        self.assertIn("protected", msg)
+
+    async def test_build_cleanup_target_branches(self):
+        """Verifies building cleanup target for a branch."""
+        with mock.patch(
+            "cleanup.get_push_remote_for_branch", return_value="origin"
+        ), mock.patch("cleanup.remote_branch_exists", return_value=True):
+            target = await cleanup.build_cleanup_target(
+                "/repo/main",
+                "/repo/worktrees/feat1",
+                "feat1",
+            )
+            self.assertEqual(target.worktree_path, "/repo/worktrees/feat1")
+            self.assertEqual(target.branch, "feat1")
+            self.assertEqual(target.remote, "origin")
+            self.assertTrue(target.remote_branch_exists)
+
+
+if __name__ == "__main__":
+    unittest.main()