diff --git a/.env.example b/.env.example
index 9bd9cbd3..a471730d 100644
--- a/.env.example
+++ b/.env.example
@@ -26,6 +26,10 @@ ORIGIN=http://localhost:13002
 #  shifted api host port, e.g. http://localhost:18000.)
 LQ_API_INTERNAL_URL=http://api:8000
 
+# Max request body donna-web accepts (adapter-node BODY_SIZE_LIMIT; its default is
+# 512K, which breaks KB uploads >0.5MB). Units K/M/G, or 'Infinity' to disable.
+DONNA_WEB_BODY_SIZE_LIMIT=512M
+
 # --- Required backend secrets (no defaults; bring-up FAILS if unset). Dev values OK locally. ---
 POSTGRES_DB=lq_ai
 POSTGRES_USER=lq_ai
diff --git a/docker-compose.release.yml b/docker-compose.release.yml
index 18a547ba..8117a205 100644
--- a/docker-compose.release.yml
+++ b/docker-compose.release.yml
@@ -253,6 +253,8 @@ services:
     environment:
       ORIGIN: ${ORIGIN:-http://localhost:3000}
       LQ_API_INTERNAL_URL: http://api:8000
+      # SvelteKit adapter-node defaults to 512K, breaking KB uploads >0.5MB with an opaque 500.
+      BODY_SIZE_LIMIT: ${DONNA_WEB_BODY_SIZE_LIMIT:-512M}
     ports:
       - '127.0.0.1:${DONNA_WEB_HOST_PORT:-3000}:3000'
     healthcheck:
diff --git a/src/lib/server/releaseCompose.test.ts b/src/lib/server/releaseCompose.test.ts
new file mode 100644
index 00000000..3dd57168
--- /dev/null
+++ b/src/lib/server/releaseCompose.test.ts
@@ -0,0 +1,22 @@
+// @vitest-environment node
+import { describe, it, expect } from 'vitest';
+import { readFileSync } from 'node:fs';
+import { resolve } from 'node:path';
+
+// docker-compose.release.yml is a hand-maintained mirror (see its header comment)
+// with no other test surface; these guards pin deploy-critical donna-web env so a
+// re-sync against vendor/lq-ai cannot silently drop it. Vitest runs from the repo
+// root, so process.cwd() resolves the top-level deploy files.
+const read = (rel: string) => readFileSync(resolve(process.cwd(), rel), 'utf8');
+
+describe('docker-compose.release.yml donna-web', () => {
+	it('raises the adapter-node body-size limit (default 512K breaks KB uploads >0.5MB)', () => {
+		const compose = read('docker-compose.release.yml');
+		const donnaWeb = compose.slice(compose.indexOf('donna-web:'));
+		expect(donnaWeb).toContain('BODY_SIZE_LIMIT: ${DONNA_WEB_BODY_SIZE_LIMIT:-512M}');
+	});
+
+	it('documents DONNA_WEB_BODY_SIZE_LIMIT in .env.example', () => {
+		expect(read('.env.example')).toMatch(/^DONNA_WEB_BODY_SIZE_LIMIT=/m);
+	});
+});