chore(deps): Adds monthly Dependabot updates

Enables automated dependency updates across uv, bun, GitHub Actions, Docker, Compose, and devcontainers
Groups updates across ecosystems to reduce PR noise
Schedules monthly runs to balance freshness and maintenance effort

.github/dependabot.yml

@@ -0,0 +1,37 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
+
+version: 2
+updates:
+  - package-ecosystem: "uv" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "monthly"
+    multi-ecosystem-group: "all"
+  - package-ecosystem: "bun"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    multi-ecosystem-group: "all"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    multi-ecosystem-group: "all"
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    multi-ecosystem-group: "all"
+  - package-ecosystem: "docker-compose"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    multi-ecosystem-group: "all"
+  - package-ecosystem: "devcontainers"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    multi-ecosystem-group: "all"