Reloading a config whose rxconfig.py imports a state-defining module raises StateValueError

[masenf]

Describe the bug

If rxconfig.py imports a project-local module that defines an rx.State subclass, reloading the config in the same RegistrationContext crashes:

StateValueError: The substate class 'appmod____my_state' has been defined multiple times.
Shadowing substate classes is not allowed.

_get_config (packages/reflex-base/src/reflex_base/config.py) drops every recorded project-local dependency from sys.modules before each load, so the next load re-imports them and re-executes any rx.State class body they contain. The second class object collides with the first, which is still registered as a substate of its parent in the current context, and the shadowing check in State.__init_subclass__ (reflex/state.py:583) fires.

This is deterministic, not a race — it happens on every reload for such a project.

To Reproduce

Two files in a project directory:

# appmod.py
import reflex as rx


class MyState(rx.State):
    value: str = ""

# rxconfig.py
import appmod  # noqa: F401
import reflex as rx

config = rx.Config(app_name="statereload")

Then:

import reflex_base.config as c
from reflex_base.registry import RegistrationContext

with RegistrationContext():
    c.get_config()
    c.reload_config()  # StateValueError

get_config(reload=True) fails the same way, since it delegates to reload_config().

Scope of the failure:

scenario	result
two separate RegistrationContexts, one load each	works — each context has its own substate registry
reload_config() / get_config(reload=True) in one context	StateValueError

Expected behavior

Reloading the config re-reads rxconfig.py from disk and returns a fresh Config, without redefining states that the previous load already registered.

Specifics (please complete the following information):

• Python Version: 3.14.7
• Reflex Version: main @ 812bb47 (reflex-base 0.9.10)
• OS: Linux

Additional context

The eviction exists so that two different project directories don't reuse each other's modules — that part works and should be preserved; interleaved loads across two projects with same-named helper modules each correctly resolve their own copy.

Two directions for a fix:

1. Scope the eviction to actual project changes — only drop the recorded deps when the project root differs from the one they were recorded under. rxconfig.py itself is still evicted every load, so a reload still re-reads it. Small and contained, but a same-root reload then stops picking up edits to helper modules imported by rxconfig.py (edits to rxconfig.py itself are still picked up).
2. Unregister the states before re-importing. This is what reload_state_module (reflex/state.py) already does for hot reload, but it lives in the reflex package and reflex_base imports nothing from reflex, so it isn't reachable from config.py today. Doing it properly likely means giving RegistrationContext an unregister-by-module capability.

Noticed while reviewing #6933; it is unrelated to that PR's sys.path changes and reproduces identically on main.

[linear-code]

ENG-12017