diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..1df6cb8
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,9 @@
+# Keep the build context small and correct. node_modules and dist are rebuilt inside
+# the image (host copies are Windows/native-built and would break Linux); .env and data
+# must never be baked into an image.
+**/node_modules
+**/dist
+.git
+**/.env
+**/data
+*.log