➕(backend) add zipstream-ng dependency

Used to stream a zip archive of a folder's content over HTTP without
buffering the whole archive in memory.

src/backend/pyproject.toml

@@ -63,6 +63,7 @@ dependencies = [
     "sentry-sdk==2.58.0",
     "url-normalize==2.2.1",
     "whitenoise==6.12.0",
+    "zipstream-ng==1.9.0",
 ]
 
 [project.urls]

src/backend/uv.lock

@@ -700,6 +700,7 @@ dependencies = [
     { name = "sentry-sdk" },
     { name = "url-normalize" },
     { name = "whitenoise" },
+    { name = "zipstream-ng" },
 ]
 
 [package.optional-dependencies]
@@ -781,6 +782,7 @@ requires-dist = [
     { name = "types-requests", marker = "extra == 'dev'", specifier = "==2.33.0.20260408" },
     { name = "url-normalize", specifier = "==2.2.1" },
     { name = "whitenoise", specifier = "==6.12.0" },
+    { name = "zipstream-ng", specifier = "==1.9.0" },
 ]
 provides-extras = ["dev"]
 
@@ -1806,3 +1808,12 @@ sdist = { url = "https://files.pythonhosted.org/packages/cb/2a/55b3f3a4ec326cd07
 wheels = [
     { url = "https://files.pythonhosted.org/packages/db/eb/d5583a11486211f3ebd4b385545ae787f32363d453c19fffd81106c9c138/whitenoise-6.12.0-py3-none-any.whl", hash = "sha256:fc5e8c572e33ebf24795b47b6a7da8da3c00cff2349f5b04c02f28d0cc5a3cc2", size = 20302, upload-time = "2026-02-27T00:05:40.086Z" },
 ]
+
+[[package]]
+name = "zipstream-ng"
+version = "1.9.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/11/f2/690a35762cf8366ce6f3b644805de970bd6a897ca44ce74184c7b2bc94e7/zipstream_ng-1.9.0.tar.gz", hash = "sha256:a0d94030822d137efbf80dfdc680603c42f804696f41147bb3db895df667daea", size = 37963, upload-time = "2025-08-29T01:03:36.323Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/de/62/c2da1c495291a52e561257d017585e08906d288035d025ccf636f6b9a266/zipstream_ng-1.9.0-py3-none-any.whl", hash = "sha256:31dc2cf617abdbf28d44f2e08c0d14c8eee2ea0ec26507a7e4d5d5f97c564b7a", size = 24852, upload-time = "2025-08-29T01:03:35.046Z" },
+]