diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..a214ad9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,13 @@
+# Environments
+.env
+.envrc
+.lock
+/.github/agents/
+/.github/instructions/
+/.github/skills/
+.venv
+env/
+venv/
+# Temporary files.
+*.patch
+*.txt
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index b2e72fd..f01bc7b 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -96,3 +96,11 @@ repos:
     rev: v1.5.0
     hooks:
       - id: detect-secrets
+  - repo: local
+    hooks:
+      - id: validate-submodules
+        name: Validate Submodule Consistency
+        entry: bash -c "git submodule status --recursive"
+        language: system
+        pass_filenames: false
+        always_run: true