chore: add developer config files

- Add .nvmrc (Node 20)
- Add .python-version (Python 3.11)
- Add .editorconfig (consistent code style)
- Add .github/dependabot.yml (automated dependency updates)

Makes contributor setup easier and keeps dependencies fresh.

Part of #180

Author: DevanshuNEU

.editorconfig

@@ -0,0 +1,21 @@
+# EditorConfig helps maintain consistent coding styles
+# https://editorconfig.org
+
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.py]
+indent_size = 4
+
+[*.md]
+trim_trailing_whitespace = false
+
+[Makefile]
+indent_style = tab

.github/dependabot.yml

@@ -0,0 +1,34 @@
+version: 2
+updates:
+  # Python dependencies
+  - package-ecosystem: "pip"
+    directory: "/backend"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: "chore(deps)"
+    labels:
+      - "dependencies"
+      - "python"
+
+  # JavaScript dependencies
+  - package-ecosystem: "npm"
+    directory: "/frontend"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: "chore(deps)"
+    labels:
+      - "dependencies"
+      - "javascript"
+
+  # GitHub Actions
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    commit-message:
+      prefix: "chore(deps)"
+    labels:
+      - "dependencies"
+      - "ci"

.nvmrc

@@ -0,0 +1 @@
+20

.python-version

@@ -0,0 +1 @@
+3.11