chore: update docs

docs/database_schema.dbml

@@ -121,11 +121,9 @@ Table tokens {
 
 Table members {
   id uuid [pk, not null, default: `uuid_generate_v7()`, note: 'UUIDv7 primary key (sortable by creation time)']
-  first_name text [not null, note: 'Member first name (min length: 1)']
-  last_name text [not null, note: 'Member last name (min length: 1)']
+  first_name text [null, note: 'Member first name (min length: 1 if present)']
+  last_name text [null, note: 'Member last name (min length: 1 if present)']
   email text [not null, unique, note: 'Member email address (5-254 chars, validated)']
-  paid boolean [null, note: 'Payment status flag']
-  phone_number text [null, note: 'Contact phone number (format: +?[0-9\- ]{6,20})']
   join_date date [null, note: 'Date when member joined club (cannot be in future)']
   exit_date date [null, note: 'Date when member left club (must be after join_date)']
   notes text [null, note: 'Additional notes about member']
@@ -149,7 +147,6 @@ Table members {
     email [name: 'members_email_idx', note: 'B-tree index for exact lookups']
     last_name [name: 'members_last_name_idx', note: 'B-tree index for name sorting']
     join_date [name: 'members_join_date_idx', note: 'B-tree index for date filters']
-    (paid) [name: 'members_paid_idx', type: btree, note: 'Partial index WHERE paid IS NOT NULL']
     membership_fee_type_id [name: 'members_membership_fee_type_id_index', note: 'B-tree index for fee type lookups']
   }
   
@@ -158,8 +155,8 @@ Table members {
     
     Core entity for membership management containing:
     - Personal information (name, email)
-    - Contact details (phone, address)
-    - Membership status (join/exit dates, payment status)
+    - Contact details (address)
+    - Membership status (join/exit dates, membership fee cycles)
     - Additional notes
     
     **Email Synchronization:**
@@ -187,12 +184,11 @@ Table members {
     - 1:N with membership_fee_cycles - billing history
     
     **Validation Rules:**
-    - first_name, last_name: min 1 character
-    - email: 5-254 characters, valid email format
+    - first_name, last_name: optional, but if present min 1 character
+    - email: 5-254 characters, valid email format (required)
     - join_date: cannot be in future
     - exit_date: must be after join_date (if both present)
-    - phone_number: matches pattern ^\+?[0-9\- ]{6,20}$
-    - postal_code: exactly 5 digits
+    - postal_code: exactly 5 digits (if present)
   '''
 }