feat: add diet entity and user lifestyle habits with data seeding support

backend/seed.yaml

@@ -9,6 +9,16 @@ roles:
   - name: reader
     description: Read-only access to analytics
 
+diets:
+  - name: normal
+    description: Standard balanced diet without specific restrictions
+  - name: vegetarian
+    description: No meat or fish; includes dairy and eggs
+  - name: vegan
+    description: Purely plant-based; no animal products
+  - name: jain
+    description: Strictly vegetarian; no root vegetables (onions, potatoes, garlic, etc.)
+
 biomarker_categories:
   - name: blood
     description: Blood cell counts and hemogram markers

backend/src/db.rs

@@ -5,7 +5,7 @@ use sea_orm::sea_query::SqliteQueryBuilder;
 
 use crate::config::Config;
 use crate::models::bio::{biomarker, biomarker_category, biomarker_entry, biomarker_reference_rule};
-use crate::models::user::{role, session, user};
+use crate::models::user::{diet, role, session, user};
 
 /// Connect to the SQLite database.
 pub async fn connect(config: &Config) -> Result<DatabaseConnection, DbErr> {
@@ -27,6 +27,7 @@ pub async fn run_migrations(db: &DatabaseConnection) -> Result<(), DbErr> {
     // Create table statements (order matters for foreign keys)
     let statements = vec![
         schema.create_table_from_entity(role::Entity),
+        schema.create_table_from_entity(diet::Entity),
         schema.create_table_from_entity(user::Entity),
         schema.create_table_from_entity(session::Entity),
         schema.create_table_from_entity(biomarker_category::Entity),

backend/src/models/user/diet.rs

@@ -0,0 +1,31 @@
+//! Diet entity - predefined diet types for user selection.
+
+use sea_orm::entity::prelude::*;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel, Serialize, Deserialize)]
+#[sea_orm(table_name = "diets")]
+pub struct Model {
+    #[sea_orm(primary_key)]
+    pub id: i32,
+
+    #[sea_orm(unique)]
+    pub name: String,
+
+    #[sea_orm(column_type = "Text", nullable)]
+    pub description: Option<String>,
+}
+
+#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
+pub enum Relation {
+    #[sea_orm(has_many = "super::user::Entity")]
+    Users,
+}
+
+impl Related<super::user::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::Users.def()
+    }
+}
+
+impl ActiveModelBehavior for ActiveModel {}

backend/src/models/user/mod.rs

@@ -1,9 +1,11 @@
 //! User and session entities for authentication.
 
+pub mod diet;
 pub mod role;
 pub mod session;
 pub mod user;
 
+pub use diet::Entity as Diet;
 pub use role::Entity as Role;
 pub use session::Entity as Session;
 pub use user::Entity as User;

backend/src/models/user/user.rs

@@ -31,6 +31,16 @@ pub struct Model {
     /// Date of birth
     pub birthdate: Option<Date>,
 
+    // Lifestyle / Habits
+    /// Whether the user smokes
+    pub smoking: Option<bool>,
+
+    /// Whether the user consumes alcohol
+    pub alcohol: Option<bool>,
+
+    /// Foreign key to diet types
+    pub diet_id: Option<i32>,
+
     pub created_at: DateTime,
     pub updated_at: DateTime,
 }
@@ -46,6 +56,13 @@ pub enum Relation {
         to = "super::role::Column::Id"
     )]
     Role,
+
+    #[sea_orm(
+        belongs_to = "super::diet::Entity",
+        from = "Column::DietId",
+        to = "super::diet::Column::Id"
+    )]
+    Diet,
 }
 
 impl Related<super::session::Entity> for Entity {
@@ -60,5 +77,10 @@ impl Related<super::role::Entity> for Entity {
     }
 }
 
-impl ActiveModelBehavior for ActiveModel {}
+impl Related<super::diet::Entity> for Entity {
+    fn to() -> RelationDef {
+        Relation::Diet.def()
+    }
+}
 
+impl ActiveModelBehavior for ActiveModel {}

backend/src/seed.rs

@@ -7,7 +7,7 @@ use std::fs;
 use std::path::Path;
 
 use crate::models::bio::{biomarker, biomarker_category, biomarker_reference_rule};
-use crate::models::user::role;
+use crate::models::user::{diet, role};
 
 // ============================================================================
 // Seed Data Structures
@@ -16,6 +16,7 @@ use crate::models::user::role;
 #[derive(Debug, Deserialize)]
 pub struct SeedData {
     pub roles: Vec<RoleSeed>,
+    pub diets: Vec<DietSeed>,
     pub biomarker_categories: Vec<BiomarkerCategorySeed>,
 }
 
@@ -36,6 +37,12 @@ pub struct BiomarkerCategorySeed {
     pub description: Option<String>,
 }
 
+#[derive(Debug, Deserialize)]
+pub struct DietSeed {
+    pub name: String,
+    pub description: Option<String>,
+}
+
 #[derive(Debug, Deserialize)]
 pub struct BiomarkerSeed {
     pub name: String,
@@ -350,6 +357,24 @@ pub async fn sync_seed_data(db: &DatabaseConnection, seed: &SeedData) -> anyhow:
         }
     }
 
+    // Sync diet types
+    for diet_seed in &seed.diets {
+        let existing = diet::Entity::find()
+            .filter(diet::Column::Name.eq(&diet_seed.name))
+            .one(db)
+            .await?;
+
+        if existing.is_none() {
+            let new_diet = diet::ActiveModel {
+                name: Set(diet_seed.name.clone()),
+                description: Set(diet_seed.description.clone()),
+                ..Default::default()
+            };
+            new_diet.insert(db).await?;
+            tracing::info!("Inserted diet: {}", diet_seed.name);
+        }
+    }
+
     // Sync biomarker categories
     for cat_seed in &seed.biomarker_categories {
         let existing = biomarker_category::Entity::find()