use new context for every request

src/app.py

@@ -23,11 +23,14 @@ with env.prefixed("ERASER_"):
     API_PASSWORD: str | None = env.str("API_PASSWORD")
     CA_BUNDLE: str | None = env.str("CA_BUNDLE", None)
 
-assert API_USER is not None
-assert API_PASSWORD is not None
-CTX = EditorAPIContext(uri=API_URL, user=API_USER, password=API_PASSWORD, priority="low")
-if CA_BUNDLE:
-    CTX.verify = CA_BUNDLE
+
+def _ctx() -> EditorAPIContext:
+    assert API_USER is not None
+    assert API_PASSWORD is not None
+    ctx = EditorAPIContext(uri=API_URL, user=API_USER, password=API_PASSWORD, priority="low")
+    if CA_BUNDLE:
+        ctx.verify = CA_BUNDLE
+    return ctx
 
 
 def resize(image: Image.Image, shortest_side: int = 768) -> Image.Image:
@@ -100,7 +103,7 @@ def process_bbox(prompts: dict[str, Any]) -> tuple[Image.Image, Image.Image]:
     if resized_img.width != img.width:
         bbox = [int(v * resized_img.width / img.width) for v in bbox]
 
-    output_image = CTX.run_one_sync(
+    output_image = _ctx().run_one_sync(
         _process,
         ProcessParams(
             image=resized_img,
@@ -116,7 +119,7 @@ def on_change_bbox(prompts: dict[str, Any] | None):
 
 def process_prompt(img: Image.Image, prompt: str) -> tuple[Image.Image, Image.Image]:
     resized_img = resize(img)
-    output_image = CTX.run_one_sync(
+    output_image = _ctx().run_one_sync(
         _process,
         ProcessParams(image=resized_img, prompt=prompt),
     )