diff --git a/.gitignore b/.gitignore
index de2f95f370..0a704f17c4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,8 @@ node_modules
 dist
 out
 build
+!website/build/
+!website/build/sites-vite-plugin.ts
 .open-next
 
 .env
diff --git a/tests/baseline/ross-website-contract.test.mjs b/tests/baseline/ross-website-contract.test.mjs
index 42c160cb93..18618b4b09 100644
--- a/tests/baseline/ross-website-contract.test.mjs
+++ b/tests/baseline/ross-website-contract.test.mjs
@@ -12,6 +12,7 @@ test("the public website is a separate build target", () => {
   const rootPackage = json("package.json");
   const websitePackage = json("website/package.json");
   assert.equal(existsSync(resolve(root, "website/.openai/hosting.json")), true);
+  assert.equal(existsSync(resolve(root, "website/build/sites-vite-plugin.ts")), true);
   assert.equal(websitePackage.name, "ross-ontario");
   assert.match(rootPackage.scripts["install:all"], /--prefix website/);
   assert.match(rootPackage.scripts.build, /build:website/);
@@ -19,6 +20,32 @@ test("the public website is a separate build target", () => {
   assert.match(rootPackage.scripts.check, /test:website/);
 });
 
+test("the website build plugin is deliberately tracked", () => {
+  const ignoreRules = read(".gitignore");
+  assert.match(ignoreRules, /!website\/build\//);
+  assert.match(ignoreRules, /!website\/build\/sites-vite-plugin\.ts/);
+  assert.match(read("website/vite.config.ts"), /\.\/build\/sites-vite-plugin/);
+});
+
+test("website shell helpers survive browser uploads without executable modes", () => {
+  const wrappers = [
+    "website/scripts/build-verified.sh",
+    "website/scripts/install-ci.sh",
+    "website/scripts/validate-artifact.sh",
+  ];
+  for (const wrapper of wrappers) {
+    assert.match(
+      read(wrapper),
+      /exec bash "\$\{script_dir\}\/sites-env\.sh" -- bash "\$0" "\$@"/,
+      wrapper,
+    );
+  }
+  assert.match(
+    read("website/scripts/build-verified.sh"),
+    /bash "\$\{script_dir\}\/validate-artifact\.sh"/,
+  );
+});
+
 test("the public website derives identity and policy from central configuration", () => {
   const central = json("config/ross-brand.json");
   const siteConfig = read("website/app/site-config.ts");
diff --git a/website/build/sites-vite-plugin.ts b/website/build/sites-vite-plugin.ts
new file mode 100644
index 0000000000..26563fdd77
--- /dev/null
+++ b/website/build/sites-vite-plugin.ts
@@ -0,0 +1,45 @@
+import { access, cp, mkdir, rm } from "node:fs/promises";
+import { resolve } from "node:path";
+import type { Plugin } from "vite";
+
+async function exists(path: string): Promise<boolean> {
+  try {
+    await access(path);
+    return true;
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code === "ENOENT") {
+      return false;
+    }
+    throw error;
+  }
+}
+
+// Packages Sites metadata and migrations after Vite finishes compiling.
+export function sites(): Plugin {
+  let root = process.cwd();
+
+  return {
+    name: "sites",
+    apply: "build",
+    configResolved(config) {
+      root = config.root;
+    },
+    async closeBundle() {
+      const outputDirectory = resolve(root, "dist", ".openai");
+      const hostingConfig = resolve(root, ".openai", "hosting.json");
+      const drizzleSource = resolve(root, "drizzle");
+
+      await rm(outputDirectory, { recursive: true, force: true });
+      await mkdir(outputDirectory, { recursive: true });
+
+      if (await exists(hostingConfig)) {
+        await cp(hostingConfig, resolve(outputDirectory, "hosting.json"));
+      }
+      if (await exists(drizzleSource)) {
+        await cp(drizzleSource, resolve(outputDirectory, "drizzle"), {
+          recursive: true,
+        });
+      }
+    },
+  };
+}
diff --git a/website/scripts/build-verified.sh b/website/scripts/build-verified.sh
index 2368b5a94d..1dea9ee58a 100644
--- a/website/scripts/build-verified.sh
+++ b/website/scripts/build-verified.sh
@@ -4,7 +4,8 @@ set -euo pipefail
 script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
 if [[ "${SITES_ENV_READY:-}" != "1" ]]; then
-  exec "${script_dir}/sites-env.sh" -- "$0" "$@"
+  # Browser-based GitHub uploads do not preserve executable file modes.
+  exec bash "${script_dir}/sites-env.sh" -- bash "$0" "$@"
 fi
 
 command -v timeout >/dev/null || {
@@ -25,4 +26,4 @@ timeout \
   "${SITES_BUILD_TIMEOUT:-3m}" \
   "${vinext}" build
 
-"${script_dir}/validate-artifact.sh"
+bash "${script_dir}/validate-artifact.sh"
diff --git a/website/scripts/install-ci.sh b/website/scripts/install-ci.sh
index 7a22fd4631..30ca9d41c3 100644
--- a/website/scripts/install-ci.sh
+++ b/website/scripts/install-ci.sh
@@ -4,7 +4,8 @@ set -euo pipefail
 script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
 if [[ "${SITES_ENV_READY:-}" != "1" ]]; then
-  exec "${script_dir}/sites-env.sh" -- "$0" "$@"
+  # Browser-based GitHub uploads do not preserve executable file modes.
+  exec bash "${script_dir}/sites-env.sh" -- bash "$0" "$@"
 fi
 
 command -v flock >/dev/null || {
diff --git a/website/scripts/validate-artifact.sh b/website/scripts/validate-artifact.sh
index 4eb9041c48..dc2532f788 100644
--- a/website/scripts/validate-artifact.sh
+++ b/website/scripts/validate-artifact.sh
@@ -4,7 +4,8 @@ set -euo pipefail
 script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
 if [[ "${SITES_ENV_READY:-}" != "1" ]]; then
-  exec "${script_dir}/sites-env.sh" -- "$0" "$@"
+  # Browser-based GitHub uploads do not preserve executable file modes.
+  exec bash "${script_dir}/sites-env.sh" -- bash "$0" "$@"
 fi
 
 worker="${SITES_PROJECT_ROOT}/dist/server/index.js"