fix(webui): respect full access in file preview

tests/channels/test_websocket_channel.py

@@ -2914,7 +2914,11 @@ def test_handle_file_preview_rejects_paths_outside_workspace(tmp_path) -> None:
     outside = tmp_path / "secret.py"
     outside.write_text("secret = True\n", encoding="utf-8")
 
-    gateway = _basic_handler(MagicMock(), workspace_path=workspace)
+    gateway = _basic_handler(
+        MagicMock(),
+        workspace_path=workspace,
+        default_restrict_to_workspace=True,
+    )
     gateway.tokens.api_tokens["tok"] = time.monotonic() + 300.0
     key = "websocket:file-preview"
     enc = quote(key, safe="")
@@ -2928,6 +2932,39 @@ def test_handle_file_preview_rejects_paths_outside_workspace(tmp_path) -> None:
     assert resp.status_code == 403
 
 
+def test_handle_file_preview_allows_paths_outside_workspace_in_full_access(tmp_path) -> None:
+    from urllib.parse import quote
+
+    from websockets.datastructures import Headers
+    from websockets.http11 import Request
+
+    workspace = tmp_path / "workspace"
+    workspace.mkdir()
+    outside = tmp_path / "notes.py"
+    outside.write_text("value = 42\n", encoding="utf-8")
+
+    gateway = _basic_handler(
+        MagicMock(),
+        workspace_path=workspace,
+        default_restrict_to_workspace=False,
+    )
+    gateway.tokens.api_tokens["tok"] = time.monotonic() + 300.0
+    key = "websocket:file-preview"
+    enc = quote(key, safe="")
+    req = Request(
+        f"/api/sessions/{enc}/file-preview?path={quote(str(outside), safe='')}",
+        Headers([("Authorization", "Bearer tok")]),
+    )
+
+    resp = gateway.http._handle_file_preview(req, enc)
+
+    assert resp.status_code == 200
+    body = json.loads(resp.body.decode())
+    assert body["path"] == str(outside.resolve())
+    assert body["display_path"] == outside.resolve().as_posix()
+    assert body["content"].splitlines() == ["value = 42"]
+
+
 def test_handle_webui_thread_get_backfills_legacy_missing_user_rows(
     tmp_path,
     monkeypatch,