[Python Environments] python.terminal.useEnvFile

Type: Bug

## Description
.envfiles

## Steps to Reproduce
1.
2.
3.

## Expected Behavior

## Actual Behavior

Environment Information

```
Extension Version: 1.36.0
Python Extension Version: 2026.4.0

Registered Environment Managers (5):
- ms-python.python:system (Global)
- ms-python.python:venv (venv)
- ms-python.python:pyenv (PyEnv)
- ms-python.python:pipenv (Pipenv)
- ms-python.python:poetry (Poetry)

Total Available Environments: 2
Environment Details:
1. Python 3.14.6 (3.14.6) - C:\Users\Lenovo\AppData\Local\Python\pythoncore-3.14-64\python.exe
2. .venv (3.14.6.final.0) (3.14.6.final.0) - c:\dharwadhubalitutor\.venv\Scripts\python.exe

Python Projects (1):
1. c:\dharwadhubalitutor
Environment: .venv (3.14.6.final.0)

Extension Settings:
Default Environment Manager: ms-python.python:venv
Default Package Manager: ms-python.python:pip
Auto-activation is "command". Activation based on first 'py-env.terminal.autoActivationType' setting which is 'command' and 'python.terminal.activateEnvironment' if the first is undefined which is 'true'.

```

Extension version: 1.36.0
VS Code version: Code 1.136.1 (a44adf7f53e00964ab890f9f8758a334f1fc15bc, 2026-09-03T05:06:41Z)
OS version: Windows_NT x64 10.0.26100
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|Intel(R) Core(TM) i5-7300U CPU @ 2.60GHz (4 x 2712)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x8086, DEVICE=0x5916 [Intel(R) HD Graphics 620], DRIVER_VENDOR=Intel, DRIVER_VERSION=23.20.16.4973 *ACTIVE*
GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.9278
Machine model name:
Machine model version:
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: enabled
multiple_raster_threads: enabled_on
opengl: enabled_on
rasterization: enabled
raw_draw: disabled_off_ok
skia_graphite: disabled_off
trees_in_viz: disabled_off
video_decode: enabled
video_encode: enabled
webgl: enabled
webgpu: enabled
webnn: disabled_off|
|Load (avg)|undefined|
|Memory (System)|15.84GB (6.43GB free)|
|Process Argv|--crash-reporter-id 4e15eab5-6066-4b91-bef3-2b00c7a737a4|
|Screen Reader|no|
|VM|0%|

A/B Experiments

```
vsliv368cf:30146710
vswsl492:30256859
pythonvspyt551cf:31249601
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
envsactivate1:31551504
478i5457:31544283
cloudbuttont:31379625
3efgi100_wstrepl:31403338
ec5jj548:31422691
cp_cls_t_966_ss:31526232
4je02754:31466945
c3h7c220:31478652
cp_cls_c_1081:31454833
conptydll_true:31498968
e9c30283:31461165
c9b86496:31447327
ei9d7968:31496641
chat:31457767
8hig5102:31480529
89g7j272:31518289
i2gc6536:31499202
52612955:31516516
23c7c724:31520045
ddid_t:31478206
hmra_i5g22:31518061
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
j0d79568:31499440
jb_cp_cls_t_632:31543129
56dj4588:31512888
32d76977:31512328
ha629193:31508444
jh5f2457_c:31540921
jbcp_cls_pctr_t:31531130
cp_intellij_t_nes:31548657
jf4hg949:31526829
ahp-both-windows:31556933
ihg5j128:31534457
9gg7f176:31542112
nes-ex-cf-euporie-03:31542868
enable_editor_pane_layout:31569726
allow-none:31555437
ac562147:31564510
c7c27ce7:31554789
1h923230:31564177
0dg73464:31554319
treatment-23-1:31555779
unuse_dynamic_mcp:31555281
0d8dfbc3:31570291
nemo-v2:31565334
0c1h4866:31566224
session-archive:31558132
5b8j3302:31564601
mangle-name-control:31572633
allow-signed-out:31574473
39a5d156:31574986
2bfb8b39:31576696
permission_prompt_treatment:1332566
ccr_pr_nudge_adoption:1319471
vsc_wsm_t:1340632
eh853263:1370294
auto_mode_treatment:1367907
1g5a5742:1376205

```

The report only identifies the python.terminal.useEnvFile setting and .envfiles; start by reproducing the behavior with the listed Python and VS Code extension versions. Clarify the expected and actual behavior, then verify that the setting handles the reported environment-file case correctly.

Written by the indexing model from the issue text.