diff --git a/Dockerfile.sidecars b/Dockerfile.sidecars
index e581856..dc7e911 100644
--- a/Dockerfile.sidecars
+++ b/Dockerfile.sidecars
@@ -66,6 +66,7 @@ COPY bot_bottle/egress_dlp_config.py /app/egress_dlp_config.py
 COPY bot_bottle/egress_addon.py      /app/egress_addon.py
 COPY bot_bottle/dlp_detectors.py     /app/dlp_detectors.py
 COPY bot_bottle/yaml_subset.py       /app/yaml_subset.py
+COPY bot_bottle/paths.py             /app/paths.py
 COPY bot_bottle/migrations.py        /app/migrations.py
 COPY bot_bottle/db_store.py          /app/db_store.py
 COPY bot_bottle/supervise_types.py   /app/supervise_types.py
diff --git a/bot_bottle/audit_store.py b/bot_bottle/audit_store.py
index 7f25e9e..c01d2bb 100644
--- a/bot_bottle/audit_store.py
+++ b/bot_bottle/audit_store.py
@@ -6,11 +6,13 @@ import sqlite3
 from pathlib import Path
 
 try:
-    from .supervise_types import AuditEntry, host_db_path
+    from .supervise_types import AuditEntry
+    from .paths import host_db_path
     from .db_store import DbStore
     from .migrations import TableMigrations
 except ImportError:
-    from supervise_types import AuditEntry, host_db_path  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
+    from supervise_types import AuditEntry  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
+    from paths import host_db_path  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
     from db_store import DbStore  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
     from migrations import TableMigrations  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
 
diff --git a/bot_bottle/backend/docker/cleanup.py b/bot_bottle/backend/docker/cleanup.py
index 254c63f..298d5fe 100644
--- a/bot_bottle/backend/docker/cleanup.py
+++ b/bot_bottle/backend/docker/cleanup.py
@@ -26,7 +26,7 @@ from __future__ import annotations
 import shutil
 import subprocess
 
-from ... import supervise as _supervise
+from ...paths import bot_bottle_root
 from ...log import info, warn
 from . import util as docker_mod
 from .bottle_cleanup_plan import DockerBottleCleanupPlan
@@ -94,7 +94,7 @@ def _list_orphan_state_dirs(
     ANY backend — used so this docker-side check doesn't reap a
     running non-docker bottle's state dir (the layout is shared
     across backends)."""
-    state_root = _supervise.bot_bottle_root() / "state"
+    state_root = bot_bottle_root() / "state"
     if not state_root.is_dir():
         return []
     orphans: list[str] = []
diff --git a/bot_bottle/bottle_state.py b/bot_bottle/bottle_state.py
index b97c89b..1ac5bb0 100644
--- a/bot_bottle/bottle_state.py
+++ b/bot_bottle/bottle_state.py
@@ -36,7 +36,7 @@ from dataclasses import dataclass
 from pathlib import Path
 from typing import cast
 
-from . import supervise as _supervise
+from .paths import bot_bottle_root
 
 
 # Directory layout: ~/.bot-bottle/state/<identity>/...
@@ -163,7 +163,7 @@ def read_metadata(identity: str) -> BottleMetadata | None:
 def bottle_state_dir(identity: str) -> Path:
     """Per-bottle state directory on the host. Created lazily by the
     write helpers; readers tolerate its absence."""
-    return _supervise.bot_bottle_root() / _STATE_SUBDIR / identity
+    return bot_bottle_root() / _STATE_SUBDIR / identity
 
 
 def per_bottle_dockerfile_path(identity: str) -> Path:
diff --git a/bot_bottle/cli/supervise.py b/bot_bottle/cli/supervise.py
index bf0766b..ff66ba6 100644
--- a/bot_bottle/cli/supervise.py
+++ b/bot_bottle/cli/supervise.py
@@ -19,7 +19,7 @@ from dataclasses import dataclass
 from datetime import datetime, timezone
 from pathlib import Path
 
-from .. import supervise as _supervise
+from ..paths import bot_bottle_root
 from ..bottle_state import read_metadata
 from ..backend.docker.egress_apply import (
     EgressApplyError,
@@ -276,7 +276,7 @@ def _write_crash_log(exc: BaseException) -> Path:
     )
     entry = f"=== supervise crash {stamp} ===\n{body}\n"
     try:
-        log_dir = _supervise.bot_bottle_root() / "logs"
+        log_dir = bot_bottle_root() / "logs"
         log_dir.mkdir(parents=True, exist_ok=True)
         path = log_dir / "supervise-crash.log"
         with path.open("a", encoding="utf-8") as fh:
diff --git a/bot_bottle/db_store.py b/bot_bottle/db_store.py
index 8950401..5d4bf37 100644
--- a/bot_bottle/db_store.py
+++ b/bot_bottle/db_store.py
@@ -11,30 +11,6 @@ except ImportError:
     from migrations import TableMigrations  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
 
 
-# The single shared host state DB. All bot-bottle SQLite stores (supervise
-# queue, audit, the orchestrator registry) co-tenant this one file — the
-# TableMigrations schema_key namespaces each store's tables.
-HOST_DB_FILENAME = "bot-bottle.db"
-
-
-def host_db_path() -> Path:
-    """Path to the shared host state DB, `<bot_bottle_root>/db/bot-bottle.db`.
-
-    Kept in its own `db/` subdirectory (not directly under the root) so a
-    backend that can only bind-mount *directories* can share this one file
-    with a sidecar without exposing the root's other contents (git-gate
-    keys, per-bottle state, ...).
-
-    Resolves `bot_bottle_root` from `supervise_types` at call time (a lazy
-    import — avoids a load-time cycle, and lets a monkey-patch of
-    `supervise_types.bot_bottle_root` propagate here)."""
-    try:
-        from . import supervise_types as _st
-    except ImportError:  # flat imports inside the sidecar bundle
-        import supervise_types as _st  # type: ignore[import-not-found,no-redef]  # pylint: disable=import-error,no-name-in-module
-    return _st.bot_bottle_root() / "db" / HOST_DB_FILENAME
-
-
 class DbVersionError(Exception):
     """Raised when the on-disk schema is behind the current migration list."""
 
@@ -80,4 +56,4 @@ class DbStore:
             pass
 
 
-__all__ = ["DbStore", "DbVersionError", "HOST_DB_FILENAME", "host_db_path"]
+__all__ = ["DbStore", "DbVersionError"]
diff --git a/bot_bottle/orchestrator/registry.py b/bot_bottle/orchestrator/registry.py
index be835c0..dd962a5 100644
--- a/bot_bottle/orchestrator/registry.py
+++ b/bot_bottle/orchestrator/registry.py
@@ -35,8 +35,9 @@ import time
 from dataclasses import dataclass
 from pathlib import Path
 
-from ..db_store import DbStore, host_db_path
+from ..db_store import DbStore
 from ..migrations import TableMigrations
+from ..paths import host_db_path
 
 # 256 bits of urandom, URL-safe — unguessable per-bottle identity token.
 IDENTITY_TOKEN_BYTES = 32
diff --git a/bot_bottle/paths.py b/bot_bottle/paths.py
new file mode 100644
index 0000000..8ac64ad
--- /dev/null
+++ b/bot_bottle/paths.py
@@ -0,0 +1,43 @@
+"""Foundational filesystem paths for bot-bottle.
+
+`bot_bottle_root()` is the app data root — state, queue, audit logs,
+git-gate keys, and the shared DB all live under it. It defaults to
+`~/.bot-bottle` and is overridable with the **`BOT_BOTTLE_ROOT`** env var.
+
+The env override is the single knob for redirecting the root: the test
+suite points it at a throwaway dir instead of monkey-patching the function
+(every module and every flat/package copy reads the same env var, so one
+override covers them all), and operators can relocate the root if needed.
+
+This module has no bot-bottle imports, so it is safe to import from any
+layer (and to COPY flat into the sidecar bundle).
+"""
+
+from __future__ import annotations
+
+import os
+from pathlib import Path
+
+# The single shared host state DB. All bot-bottle SQLite stores (supervise
+# queue, audit, the orchestrator registry) co-tenant this one file — the
+# TableMigrations schema_key namespaces each store's tables.
+HOST_DB_FILENAME = "bot-bottle.db"
+
+
+def bot_bottle_root() -> Path:
+    """The app data root — `$BOT_BOTTLE_ROOT` if set, else `~/.bot-bottle`."""
+    override = os.environ.get("BOT_BOTTLE_ROOT")
+    return Path(override) if override else Path.home() / ".bot-bottle"
+
+
+def host_db_path() -> Path:
+    """Path to the shared host state DB, `<root>/db/bot-bottle.db`.
+
+    Kept in its own `db/` subdirectory (not directly under the root) so a
+    backend that can only bind-mount *directories* can share this one file
+    with a sidecar without exposing the root's other contents (git-gate
+    keys, per-bottle state, ...)."""
+    return bot_bottle_root() / "db" / HOST_DB_FILENAME
+
+
+__all__ = ["HOST_DB_FILENAME", "bot_bottle_root", "host_db_path"]
diff --git a/bot_bottle/queue_store.py b/bot_bottle/queue_store.py
index 0fe3295..cd6b188 100644
--- a/bot_bottle/queue_store.py
+++ b/bot_bottle/queue_store.py
@@ -7,11 +7,13 @@ import sqlite3
 from pathlib import Path
 
 try:
-    from .supervise_types import Proposal, Response, host_db_path
+    from .supervise_types import Proposal, Response
+    from .paths import host_db_path
     from .db_store import DbStore
     from .migrations import TableMigrations
 except ImportError:
-    from supervise_types import Proposal, Response, host_db_path  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
+    from supervise_types import Proposal, Response  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
+    from paths import host_db_path  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
     from db_store import DbStore  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
     from migrations import TableMigrations  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
 
diff --git a/bot_bottle/store_manager.py b/bot_bottle/store_manager.py
index 70b1f46..bb1c494 100644
--- a/bot_bottle/store_manager.py
+++ b/bot_bottle/store_manager.py
@@ -23,13 +23,10 @@ class StoreManager:
 
     def __init__(self, db_path: Path | None = None) -> None:
         if db_path is None:
-            # Lazy import to avoid a circular dependency: supervise imports
-            # StoreManager at module level; StoreManager must not import
-            # supervise at module level in return.
             try:
-                from .supervise import host_db_path
+                from .paths import host_db_path
             except ImportError:
-                from supervise import host_db_path  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
+                from paths import host_db_path  # type: ignore[import-not-found]  # pylint: disable=import-error,no-name-in-module
             db_path = host_db_path()
         self.db_path = db_path
 
diff --git a/bot_bottle/supervise.py b/bot_bottle/supervise.py
index cfa6a51..d1d9596 100644
--- a/bot_bottle/supervise.py
+++ b/bot_bottle/supervise.py
@@ -41,7 +41,6 @@ try:
     from .supervise_types import (
         ACTION_OPERATOR_EDIT,
         AuditEntry,
-        HOST_DB_FILENAME,
         Proposal,
         Response,
         STATUSES,
@@ -54,13 +53,11 @@ try:
         TOOL_EGRESS_TOKEN_ALLOW,
         TOOL_GITLEAKS_ALLOW,
         TOOL_LIST_EGRESS_ROUTES,
-        bot_bottle_root,
     )
 except ImportError:
     from supervise_types import (  # type: ignore[import-not-found,no-redef]  # pylint: disable=import-error,no-name-in-module
         ACTION_OPERATOR_EDIT,
         AuditEntry,
-        HOST_DB_FILENAME,
         Proposal,
         Response,
         STATUSES,
@@ -73,10 +70,15 @@ except ImportError:
         TOOL_EGRESS_TOKEN_ALLOW,
         TOOL_GITLEAKS_ALLOW,
         TOOL_LIST_EGRESS_ROUTES,
-        bot_bottle_root,
     )
 
 
+try:
+    from .paths import bot_bottle_root, host_db_path
+except ImportError:  # flat imports inside the sidecar bundle
+    from paths import bot_bottle_root, host_db_path  # type: ignore[import-not-found,no-redef]  # pylint: disable=import-error,no-name-in-module
+
+
 SUPERVISE_HOSTNAME = "supervise"
 SUPERVISE_PORT = 9100
 
@@ -106,16 +108,6 @@ def audit_dir() -> Path:
     return bot_bottle_root() / "audit"
 
 
-def host_db_path() -> Path:
-    # Calls bot_bottle_root() through this module's globals so that patches
-    # on supervise.bot_bottle_root propagate to callers going through
-    # supervise.host_db_path().
-    #
-    # Kept in its own "db" subdirectory (see supervise_types.host_db_path
-    # for why) — must stay in sync with that copy.
-    return bot_bottle_root() / "db" / HOST_DB_FILENAME
-
-
 def audit_log_path(component: str, slug: str) -> Path:
     return audit_dir() / f"{component}-{slug}.log"
 
diff --git a/bot_bottle/supervise_types.py b/bot_bottle/supervise_types.py
index 1e579f0..d62343d 100644
--- a/bot_bottle/supervise_types.py
+++ b/bot_bottle/supervise_types.py
@@ -1,14 +1,11 @@
-"""Shared types and path helpers for supervise stores (PRD 0013).
+"""Shared types for supervise stores (PRD 0013).
 
 Extracted from supervise.py so queue_store and audit_store can import
-Proposal, Response, AuditEntry, and host_db_path without creating a
-circular import (supervise imports from queue_store/audit_store and
-vice-versa).
+Proposal, Response, and AuditEntry without creating a circular import
+(supervise imports from queue_store/audit_store and vice-versa).
 
-host_db_path / HOST_DB_FILENAME now live in db_store (shared DB infra) and
-are re-exported here for the historical import path. db_store.host_db_path
-resolves bot_bottle_root from this module lazily, so patching
-supervise_types.bot_bottle_root still propagates to the DB path.
+The path helpers (`bot_bottle_root`, `host_db_path`, `HOST_DB_FILENAME`)
+live in `paths` — import them from there.
 """
 
 from __future__ import annotations
@@ -17,16 +14,6 @@ import dataclasses
 import uuid
 from dataclasses import dataclass
 from datetime import datetime, timezone
-from pathlib import Path
-
-# host_db_path / HOST_DB_FILENAME now live in db_store (shared DB infra);
-# re-exported here for the historical import path. db_store resolves
-# bot_bottle_root from this module lazily, so patching
-# supervise_types.bot_bottle_root still propagates.
-try:
-    from .db_store import HOST_DB_FILENAME, host_db_path
-except ImportError:  # flat imports inside the sidecar bundle
-    from db_store import HOST_DB_FILENAME, host_db_path  # type: ignore[import-not-found,no-redef]  # pylint: disable=import-error,no-name-in-module
 
 TOOL_EGRESS_BLOCK = "egress-block"
 TOOL_EGRESS_ALLOW = "egress-allow"
@@ -49,10 +36,6 @@ STATUSES: tuple[str, ...] = (STATUS_APPROVED, STATUS_MODIFIED, STATUS_REJECTED)
 ACTION_OPERATOR_EDIT = "operator-edit"
 
 
-def bot_bottle_root() -> Path:
-    return Path.home() / ".bot-bottle"
-
-
 def _require_str(raw: dict[str, object], key: str) -> str:
     value = raw.get(key)
     if not isinstance(value, str):
@@ -164,7 +147,6 @@ class AuditEntry:
 __all__ = [
     "ACTION_OPERATOR_EDIT",
     "AuditEntry",
-    "HOST_DB_FILENAME",
     "Proposal",
     "Response",
     "STATUSES",
@@ -177,6 +159,4 @@ __all__ = [
     "TOOL_EGRESS_TOKEN_ALLOW",
     "TOOL_GITLEAKS_ALLOW",
     "TOOL_LIST_EGRESS_ROUTES",
-    "bot_bottle_root",
-    "host_db_path",
 ]
diff --git a/tests/unit/__init__.py b/tests/unit/__init__.py
index da5784b..7e69d1d 100644
--- a/tests/unit/__init__.py
+++ b/tests/unit/__init__.py
@@ -10,8 +10,12 @@ and unisolated tests otherwise pollute the developer's home dir.
 
 Individual tests that need their own ``HOME`` still override
 ``os.environ['HOME']`` and restore it; they now restore to this isolated
-dir rather than the real one, so isolation holds either way. Tests that
-patch ``supervise.bot_bottle_root`` directly are unaffected.
+dir rather than the real one, so isolation holds either way.
+
+Tests that need their own app-data root call ``use_bottle_root`` (below),
+which sets ``BOT_BOTTLE_ROOT`` — the supported override read by
+``paths.bot_bottle_root`` — instead of monkey-patching. One env setting
+covers every module and every flat/package copy of the helper.
 """
 
 from __future__ import annotations
@@ -20,6 +24,9 @@ import atexit
 import os
 import shutil
 import tempfile
+from collections.abc import Callable
+from pathlib import Path
+from unittest import mock
 
 _real_home = os.environ.get("HOME")
 _tmp_home = tempfile.mkdtemp(prefix="bot-bottle-unit-home.")
@@ -35,3 +42,15 @@ def _restore_home() -> None:
 
 
 atexit.register(_restore_home)
+
+
+def use_bottle_root(root: Path) -> Callable[[], None]:
+    """Redirect ``paths.bot_bottle_root()`` to ``root`` by setting
+    ``BOT_BOTTLE_ROOT`` — the supported override. Returns a callable that
+    undoes it (store it as the test's restore hook, or pass to addCleanup).
+
+    Replaces monkey-patching ``supervise.bot_bottle_root``; one env var
+    covers every module and the flat/package copies alike (they all read it)."""
+    patcher = mock.patch.dict(os.environ, {"BOT_BOTTLE_ROOT": str(root)})
+    patcher.start()
+    return patcher.stop
diff --git a/tests/unit/test_backend_freezer.py b/tests/unit/test_backend_freezer.py
index 40241b3..3cb7d54 100644
--- a/tests/unit/test_backend_freezer.py
+++ b/tests/unit/test_backend_freezer.py
@@ -7,7 +7,8 @@ import unittest
 from pathlib import Path
 from unittest.mock import patch
 
-from bot_bottle import supervise, bottle_state
+from bot_bottle import bottle_state
+from tests.unit import use_bottle_root
 from bot_bottle.backend import ActiveAgent
 from bot_bottle.backend.freeze import get_freezer
 from bot_bottle.backend.docker.freezer import DockerFreezer
@@ -18,13 +19,7 @@ from bot_bottle.backend.firecracker.freezer import FirecrackerFreezer
 class _FakeHomeMixin:
     def _setup_fake_home(self):
         self._tmp = tempfile.TemporaryDirectory(prefix="freezer-test.")
-        original = supervise.bot_bottle_root
-
-        def fake_root() -> Path:
-            return Path(self._tmp.name) / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
-        self._restore = lambda: setattr(supervise, "bot_bottle_root", original)
+        self._restore = use_bottle_root(Path(self._tmp.name) / ".bot-bottle")
 
     def _teardown_fake_home(self):
         self._restore()
diff --git a/tests/unit/test_backend_prepare.py b/tests/unit/test_backend_prepare.py
index 6423ccd..6013229 100644
--- a/tests/unit/test_backend_prepare.py
+++ b/tests/unit/test_backend_prepare.py
@@ -13,7 +13,7 @@ from pathlib import Path
 from unittest.mock import patch
 
 from bot_bottle import bottle_state
-from bot_bottle import supervise
+from tests.unit import use_bottle_root
 from bot_bottle.backend import BottleSpec
 from bot_bottle.backend.docker import DockerBottleBackend
 from bot_bottle.backend.resolve_common import mint_slug
@@ -55,11 +55,10 @@ class _FakeStateMixin:
     def setUp(self) -> None:
         self.tmp = tempfile.TemporaryDirectory(prefix="backend-prepare.")
         self.root = Path(self.tmp.name) / ".bot-bottle"
-        self.original_root = supervise.bot_bottle_root
-        supervise.bot_bottle_root = lambda: self.root  # type: ignore[assignment]
+        self._restore = use_bottle_root(self.root)
 
     def tearDown(self) -> None:
-        supervise.bot_bottle_root = self.original_root  # type: ignore[assignment]
+        self._restore()
         self.tmp.cleanup()
 
 
diff --git a/tests/unit/test_backend_workspace.py b/tests/unit/test_backend_workspace.py
index f57fa02..a7463f3 100644
--- a/tests/unit/test_backend_workspace.py
+++ b/tests/unit/test_backend_workspace.py
@@ -13,7 +13,7 @@ from pathlib import Path
 from unittest.mock import MagicMock, call, patch
 
 from bot_bottle import bottle_state
-from bot_bottle import supervise
+from tests.unit import use_bottle_root
 from bot_bottle.backend import Bottle, BottleSpec, ExecResult
 from bot_bottle.backend.docker import DockerBottleBackend
 from bot_bottle.backend.firecracker import FirecrackerBottleBackend
@@ -55,11 +55,10 @@ class _FakeStateMixin:
         self.tmp_dir = tempfile.TemporaryDirectory(prefix="backend-workspace.")
         self.tmp = Path(self.tmp_dir.name)
         self.root = self.tmp / ".bot-bottle"
-        self.original_root = supervise.bot_bottle_root
-        supervise.bot_bottle_root = lambda: self.root  # type: ignore[assignment]
+        self._restore = use_bottle_root(self.root)
 
     def tearDown(self) -> None:
-        supervise.bot_bottle_root = self.original_root  # type: ignore[assignment]
+        self._restore()
         self.tmp_dir.cleanup()
 
 
diff --git a/tests/unit/test_bottle_state.py b/tests/unit/test_bottle_state.py
index c9abd92..df7a200 100644
--- a/tests/unit/test_bottle_state.py
+++ b/tests/unit/test_bottle_state.py
@@ -6,7 +6,7 @@ import tempfile
 import unittest
 from pathlib import Path
 
-from bot_bottle import supervise
+from tests.unit import use_bottle_root
 from bot_bottle import bottle_state
 from bot_bottle.bottle_state import (
     BottleMetadata,
@@ -18,13 +18,7 @@ from bot_bottle.bottle_state import (
 class _FakeHomeMixin:
     def _setup_fake_home(self):
         self._tmp = tempfile.TemporaryDirectory(prefix="bottle-state-test.")
-        original = supervise.bot_bottle_root
-
-        def fake_root() -> Path:
-            return Path(self._tmp.name) / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
-        self._restore = lambda: setattr(supervise, "bot_bottle_root", original)
+        self._restore = use_bottle_root(Path(self._tmp.name) / ".bot-bottle")
 
     def _teardown_fake_home(self):
         self._restore()
diff --git a/tests/unit/test_cli_commit.py b/tests/unit/test_cli_commit.py
index 2dd2708..6a7e7ff 100644
--- a/tests/unit/test_cli_commit.py
+++ b/tests/unit/test_cli_commit.py
@@ -8,7 +8,7 @@ from pathlib import Path
 from unittest.mock import MagicMock, patch
 
 from bot_bottle.cli.commit import cmd_commit
-from bot_bottle import supervise
+from tests.unit import use_bottle_root
 from bot_bottle import bottle_state
 from bot_bottle.backend.freeze import CommitCancelled
 
@@ -16,13 +16,7 @@ from bot_bottle.backend.freeze import CommitCancelled
 class _FakeHomeMixin:
     def _setup_fake_home(self):
         self._tmp = tempfile.TemporaryDirectory(prefix="cli-commit-test.")
-        original = supervise.bot_bottle_root
-
-        def fake_root() -> Path:
-            return Path(self._tmp.name) / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
-        self._restore = lambda: setattr(supervise, "bot_bottle_root", original)
+        self._restore = use_bottle_root(Path(self._tmp.name) / ".bot-bottle")
 
     def _teardown_fake_home(self):
         self._restore()
diff --git a/tests/unit/test_cli_start_settle.py b/tests/unit/test_cli_start_settle.py
index 9a94ba5..4b1c405 100644
--- a/tests/unit/test_cli_start_settle.py
+++ b/tests/unit/test_cli_start_settle.py
@@ -8,7 +8,7 @@ import tempfile
 import unittest
 from pathlib import Path
 
-from bot_bottle import supervise
+from tests.unit import use_bottle_root
 from bot_bottle import bottle_state
 from bot_bottle.cli import start as start_mod
 
@@ -16,15 +16,10 @@ from bot_bottle.cli import start as start_mod
 class _FakeHomeMixin:
     def _setup_fake_home(self):
         self._tmp = tempfile.TemporaryDirectory(prefix="cli-start-settle.")
-        self._original = supervise.bot_bottle_root
-
-        def fake_root() -> Path:
-            return Path(self._tmp.name) / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
+        self._restore = use_bottle_root(Path(self._tmp.name) / ".bot-bottle")
 
     def _teardown_fake_home(self):
-        supervise.bot_bottle_root = self._original  # type: ignore[assignment]
+        self._restore()
         self._tmp.cleanup()
 
 
diff --git a/tests/unit/test_docker_cleanup.py b/tests/unit/test_docker_cleanup.py
index aeab400..730f20f 100644
--- a/tests/unit/test_docker_cleanup.py
+++ b/tests/unit/test_docker_cleanup.py
@@ -15,7 +15,7 @@ import tempfile
 import unittest
 from pathlib import Path
 
-from bot_bottle import supervise
+from tests.unit import use_bottle_root
 from bot_bottle import bottle_state
 from bot_bottle.backend.docker.cleanup import _list_orphan_state_dirs
 
@@ -23,13 +23,7 @@ from bot_bottle.backend.docker.cleanup import _list_orphan_state_dirs
 class _FakeHomeMixin:
     def _setup_fake_home(self) -> None:
         self._tmp = tempfile.TemporaryDirectory(prefix="docker-cleanup-test.")
-        original = supervise.bot_bottle_root
-
-        def fake_root() -> Path:
-            return Path(self._tmp.name) / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
-        self._restore = lambda: setattr(supervise, "bot_bottle_root", original)
+        self._restore = use_bottle_root(Path(self._tmp.name) / ".bot-bottle")
 
     def _teardown_fake_home(self) -> None:
         self._restore()
diff --git a/tests/unit/test_docker_enumerate_active.py b/tests/unit/test_docker_enumerate_active.py
index b6aca74..c774c28 100644
--- a/tests/unit/test_docker_enumerate_active.py
+++ b/tests/unit/test_docker_enumerate_active.py
@@ -23,7 +23,7 @@ import tempfile
 import unittest
 from pathlib import Path
 
-from bot_bottle import supervise
+from tests.unit import use_bottle_root
 from bot_bottle import bottle_state
 from bot_bottle.backend.docker import enumerate as _enumerate
 
@@ -75,13 +75,7 @@ class TestParseServicesByProject(unittest.TestCase):
 class _FakeHomeMixin:
     def _setup_fake_home(self) -> None:
         self._tmp = tempfile.TemporaryDirectory(prefix="enum-active.")
-        original = supervise.bot_bottle_root
-
-        def fake_root() -> Path:
-            return Path(self._tmp.name) / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
-        self._restore_home = lambda: setattr(supervise, "bot_bottle_root", original)
+        self._restore_home = use_bottle_root(Path(self._tmp.name) / ".bot-bottle")
 
     def _teardown_fake_home(self) -> None:
         self._restore_home()
diff --git a/tests/unit/test_egress_apply.py b/tests/unit/test_egress_apply.py
index de51c57..12d3b1a 100644
--- a/tests/unit/test_egress_apply.py
+++ b/tests/unit/test_egress_apply.py
@@ -8,7 +8,7 @@ from pathlib import Path
 from types import SimpleNamespace
 from unittest.mock import patch
 
-from bot_bottle import supervise
+from tests.unit import use_bottle_root
 from bot_bottle.backend.egress_apply import EgressApplyError
 from bot_bottle.backend.docker.egress_apply import applicator
 
@@ -67,14 +67,8 @@ class TestValidateRoutesContent(unittest.TestCase):
 class TestApplyRoutesChange(unittest.TestCase):
     def setUp(self):
         self._tmp = tempfile.TemporaryDirectory(prefix="egress-apply-test.")
-        original = supervise.bot_bottle_root
-
-        def fake_root() -> Path:
-            return Path(self._tmp.name) / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
-        self.addCleanup(lambda: setattr(supervise, "bot_bottle_root", original))
         self.addCleanup(self._tmp.cleanup)
+        self.addCleanup(use_bottle_root(Path(self._tmp.name) / ".bot-bottle"))
 
     def test_writes_live_routes_and_signals_reload(self):
         calls: list[list[str]] = []
diff --git a/tests/unit/test_supervise.py b/tests/unit/test_supervise.py
index bc69b89..01198a8 100644
--- a/tests/unit/test_supervise.py
+++ b/tests/unit/test_supervise.py
@@ -8,7 +8,7 @@ from datetime import datetime, timezone
 from pathlib import Path
 
 from bot_bottle import supervise
-from bot_bottle import supervise_types as sv_types
+from tests.unit import use_bottle_root
 from bot_bottle.audit_store import AuditStore
 from bot_bottle.queue_store import QueueStore
 from bot_bottle.supervise import (
@@ -123,20 +123,7 @@ class TestQueueIO(unittest.TestCase):
         self._tmp.cleanup()
 
     def _patch_home(self, fake_home: Path):
-        original_sv = supervise.bot_bottle_root
-        original_svt = sv_types.bot_bottle_root
-
-        def fake_root() -> Path:
-            return fake_home / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
-        sv_types.bot_bottle_root = fake_root  # type: ignore[assignment]
-
-        def restore() -> None:
-            supervise.bot_bottle_root = original_sv  # type: ignore[assignment]
-            sv_types.bot_bottle_root = original_svt  # type: ignore[assignment]
-
-        return restore
+        return use_bottle_root(fake_home / ".bot-bottle")
 
     def test_write_and_read_proposal(self):
         p = _proposal()
@@ -240,20 +227,7 @@ class TestAuditLog(unittest.TestCase):
         self._tmp.cleanup()
 
     def _patch_home(self, fake_home: Path):
-        original_sv = supervise.bot_bottle_root
-        original_svt = sv_types.bot_bottle_root
-
-        def fake_root() -> Path:
-            return fake_home / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
-        sv_types.bot_bottle_root = fake_root  # type: ignore[assignment]
-
-        def restore() -> None:
-            supervise.bot_bottle_root = original_sv  # type: ignore[assignment]
-            sv_types.bot_bottle_root = original_svt  # type: ignore[assignment]
-
-        return restore
+        return use_bottle_root(fake_home / ".bot-bottle")
 
     def test_write_then_read_single_entry(self):
         e = AuditEntry(
@@ -400,20 +374,7 @@ class TestSupervisePrepare(unittest.TestCase):
         self._tmp.cleanup()
 
     def _patch_home(self, fake_home: Path):
-        original_sv = supervise.bot_bottle_root
-        original_svt = sv_types.bot_bottle_root
-
-        def fake_root() -> Path:
-            return fake_home / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
-        sv_types.bot_bottle_root = fake_root  # type: ignore[assignment]
-
-        def restore() -> None:
-            supervise.bot_bottle_root = original_sv  # type: ignore[assignment]
-            sv_types.bot_bottle_root = original_svt  # type: ignore[assignment]
-
-        return restore
+        return use_bottle_root(fake_home / ".bot-bottle")
 
     def test_prepare_creates_queue(self):
         plan = _StubSupervise().prepare("dev", self.stage_dir)
diff --git a/tests/unit/test_supervise_cli.py b/tests/unit/test_supervise_cli.py
index 9903da3..9b74ec5 100644
--- a/tests/unit/test_supervise_cli.py
+++ b/tests/unit/test_supervise_cli.py
@@ -12,7 +12,7 @@ from pathlib import Path
 from unittest.mock import patch
 
 from bot_bottle import supervise
-from bot_bottle import supervise_types as sv_types
+from tests.unit import use_bottle_root
 from bot_bottle.audit_store import AuditStore
 from bot_bottle.cli import supervise as supervise_cli
 from bot_bottle.queue_store import QueueStore
@@ -55,20 +55,7 @@ class _FakeHomeMixin:
 
     def _setup_fake_home(self):
         self._tmp = tempfile.TemporaryDirectory(prefix="supervise-test.")
-        original_sv = supervise.bot_bottle_root
-        original_svt = sv_types.bot_bottle_root
-
-        def fake_root() -> Path:
-            return Path(self._tmp.name) / ".bot-bottle"
-
-        supervise.bot_bottle_root = fake_root  # type: ignore[assignment]
-        sv_types.bot_bottle_root = fake_root  # type: ignore[assignment]
-
-        def restore() -> None:
-            supervise.bot_bottle_root = original_sv  # type: ignore[assignment]
-            sv_types.bot_bottle_root = original_svt  # type: ignore[assignment]
-
-        self._restore_home = restore
+        self._restore_home = use_bottle_root(Path(self._tmp.name) / ".bot-bottle")
         QueueStore("").migrate()
         AuditStore().migrate()
 
diff --git a/tests/unit/test_supervise_cli_crash_logging.py b/tests/unit/test_supervise_cli_crash_logging.py
index 56cb6f0..3fca465 100644
--- a/tests/unit/test_supervise_cli_crash_logging.py
+++ b/tests/unit/test_supervise_cli_crash_logging.py
@@ -11,12 +11,13 @@ from __future__ import annotations
 
 import contextlib
 import io
+import os
 import tempfile
 import unittest
 from pathlib import Path
 from unittest import mock
 
-from bot_bottle import supervise
+from tests.unit import use_bottle_root
 from bot_bottle.cli import supervise as supervise_cli
 from bot_bottle.log import Die, die
 
@@ -45,12 +46,11 @@ class _FakeHomeMixin:
 
     def _setup_fake_home(self):
         self._tmp = tempfile.TemporaryDirectory(prefix="supervise-crash-test.")
-        self._orig_root = supervise.bot_bottle_root
         self._root = Path(self._tmp.name) / ".bot-bottle"
-        supervise.bot_bottle_root = lambda: self._root  # type: ignore[assignment]
+        self._restore_root = use_bottle_root(self._root)
 
     def _teardown_fake_home(self):
-        supervise.bot_bottle_root = self._orig_root  # type: ignore[assignment]
+        self._restore_root()
         self._tmp.cleanup()
 
 
@@ -127,11 +127,11 @@ class TestWriteCrashLog(_FakeHomeMixin, unittest.TestCase):
         # OSError and the helper must fall back to a tempfile.
         bad = Path(self._tmp.name) / "not-a-dir"
         bad.write_text("x")
-        supervise.bot_bottle_root = lambda: bad  # type: ignore[assignment]
-        try:
-            raise RuntimeError("explode2")
-        except RuntimeError as e:
-            path = supervise_cli._write_crash_log(e)
+        with mock.patch.dict(os.environ, {"BOT_BOTTLE_ROOT": str(bad)}):
+            try:
+                raise RuntimeError("explode2")
+            except RuntimeError as e:
+                path = supervise_cli._write_crash_log(e)
         self.assertTrue(path.exists())
         self.assertIn("explode2", path.read_text())
 
diff --git a/tests/unit/test_supervise_server.py b/tests/unit/test_supervise_server.py
index 9ea47e5..a29f032 100644
--- a/tests/unit/test_supervise_server.py
+++ b/tests/unit/test_supervise_server.py
@@ -10,6 +10,8 @@ import unittest
 from pathlib import Path
 from unittest.mock import patch
 
+from tests.unit import use_bottle_root
+
 
 # The server module loads `supervise` via same-directory import inside
 # the container (Dockerfile.supervise WORKDIRs into /app). For tests
@@ -19,10 +21,8 @@ sys.path.insert(0, str(Path(__file__).resolve().parent.parent.parent / "bot_bott
 import supervise as _sv  # noqa: E402  # type: ignore
 import queue_store as _qs  # noqa: E402  # type: ignore
 import audit_store as _as  # noqa: E402  # type: ignore
-import supervise_types as svt_flat  # noqa: E402  # type: ignore
 
 from bot_bottle import supervise_server  # noqa: E402
-from bot_bottle import supervise_types as svt_pkg  # noqa: E402
 from bot_bottle.supervise_server import (
     ERR_INTERNAL,
     ERR_INVALID_PARAMS,
@@ -279,23 +279,7 @@ class TestHandleToolsCall(unittest.TestCase):
         self._tmp.cleanup()
 
     def _patch_home(self, fake_home: Path):
-        original_sv = _sv.bot_bottle_root
-        original_flat = svt_flat.bot_bottle_root
-        original_pkg = svt_pkg.bot_bottle_root
-
-        def fake_root() -> Path:
-            return fake_home / ".bot-bottle"
-
-        _sv.bot_bottle_root = fake_root  # type: ignore[assignment]
-        svt_flat.bot_bottle_root = fake_root  # type: ignore[assignment]
-        svt_pkg.bot_bottle_root = fake_root  # type: ignore[assignment]
-
-        def restore() -> None:
-            _sv.bot_bottle_root = original_sv  # type: ignore[assignment]
-            svt_flat.bot_bottle_root = original_flat  # type: ignore[assignment]
-            svt_pkg.bot_bottle_root = original_pkg  # type: ignore[assignment]
-
-        return restore
+        return use_bottle_root(fake_home / ".bot-bottle")
 
     def _respond_when_proposal_appears(self, status: str, notes: str = "") -> threading.Thread:
         """Background thread: poll the queue for a fresh proposal, write a