feat: Add validation constraints and tests for CustomField and CustomFieldValue

lib/membership/custom_field.ex

@@ -15,17 +15,18 @@ defmodule Mv.Membership.CustomField do
   - `required` - If true, all members must have this custom field (future feature)
 
   ## Supported Value Types
-  - `:string` - Text data (unlimited length)
+  - `:string` - Text data (max 10,000 characters)
   - `:integer` - Numeric data (64-bit integers)
   - `:boolean` - True/false flags
   - `:date` - Date values (no time component)
-  - `:email` - Validated email addresses
+  - `:email` - Validated email addresses (max 254 characters)
 
   ## Relationships
   - `has_many :custom_field_values` - All custom field values of this type
 
   ## Constraints
   - Name must be unique across all custom fields
+  - Name maximum length: 100 characters
   - Cannot delete a custom field that has existing custom field values (RESTRICT)
 
   ## Examples
@@ -60,14 +61,26 @@ defmodule Mv.Membership.CustomField do
   attributes do
     uuid_primary_key :id
 
-    attribute :name, :string, allow_nil?: false, public?: true
+    attribute :name, :string,
+      allow_nil?: false,
+      public?: true,
+      constraints: [
+        max_length: 100,
+        trim?: true
+      ]
 
     attribute :value_type, :atom,
       constraints: [one_of: [:string, :integer, :boolean, :date, :email]],
       allow_nil?: false,
       description: "Defines the datatype `CustomFieldValue.value` is interpreted as"
 
-    attribute :description, :string, allow_nil?: true, public?: true
+    attribute :description, :string,
+      allow_nil?: true,
+      public?: true,
+      constraints: [
+        max_length: 500,
+        trim?: true
+      ]
 
     attribute :immutable, :boolean,
       default: false,