feat: add ty type checking support and fix type issues

- Add ty.toml configuration with Django project root
- Add py.typed marker for type checking
- Fix type issues across codebase:
  - Add type ignore comments for redis.exceptions imports
  - Fix django.db.models.functions imports in utils
  - Fix getattr usage in accounts/forms
  - Remove unnecessary type annotations in dashboard/forms
- Configure ty to exclude migrations and respect ignore files
- All ty checks now pass (29 diagnostics -> 0)

package.json

@@ -1,26 +1,26 @@
 {
-    "scripts": {
-        "format": "prettier --write .",
-        "format:check": "prettier --check .",
-        "lint:md": "markdownlint-cli2 \"**/*.md\"",
-        "lint:md:fix": "bun lint:md -- --fix"
+  "scripts": {
+    "format": "prettier --write .",
+    "format:check": "prettier --check .",
+    "lint:md": "markdownlint-cli2 \"**/*.md\"",
+    "lint:md:fix": "bun lint:md -- --fix"
+  },
+  "devDependencies": {
+    "markdownlint-cli2": "^0.18.1",
+    "prettier": "^3.6.2",
+    "prettier-plugin-jinja-template": "^2.1.0",
+    "prettier-plugin-packagejson": "^2.5.19"
+  },
+  "markdownlint-cli2": {
+    "config": {
+      "MD013": false,
+      "MD033": false
     },
-    "devDependencies": {
-        "markdownlint-cli2": "^0.18.1",
-        "prettier": "^3.6.2",
-        "prettier-plugin-jinja-template": "^2.1.0",
-        "prettier-plugin-packagejson": "^2.5.19"
-    },
-    "markdownlint-cli2": {
-        "config": {
-            "MD013": false,
-            "MD033": false
-        },
-        "ignores": [
-            ".git",
-            ".trunk",
-            ".venv",
-            "node_modules"
-        ]
-    }
+    "ignores": [
+      ".git",
+      ".trunk",
+      ".venv",
+      "node_modules"
+    ]
+  }
 }