Friends functionality (#90)

### Description

Implements and closes #86

### Game

Robocraft

### Please confirm

- [x] I am the legal owner or represent the owner of all work submitted
- [x] I consent to my submission being added to this FOSS project
- [ ] This PR used LLMs to generate some or all of the code changes

Reviewed-on: https://git.ngram.ca/OpenJam/rc-servers/pulls/90
Co-authored-by: NG (Graham) <ngniusness@gmail.com>
Co-committed-by: NG (Graham) <ngniusness@gmail.com>

rc_database/src/migration/m20260215_000001_create_friend_table.rs

@@ -0,0 +1,53 @@
+use sea_orm_migration::prelude::*;
+
+pub struct Migration;
+
+impl MigrationName for Migration {
+    fn name(&self) -> &str {
+        "m20260215_000001_create_friend_table"
+    }
+}
+
+#[async_trait::async_trait]
+impl MigrationTrait for Migration {
+    // Define how to apply this migration: Create the Friends table.
+    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .create_table(
+                Table::create()
+                    .table(crate::schema::friend::Entity)
+                    .col(
+                        ColumnDef::new(crate::schema::friend::Column::Id)
+                            .integer()
+                            .not_null()
+                            .auto_increment()
+                            .primary_key(),
+                    )
+                    .col(ColumnDef::new(crate::schema::factory::vehicle::Column::CreationTime).big_integer().not_null())
+                    .col(ColumnDef::new(crate::schema::friend::Column::FriendSource).integer().not_null())
+                    .foreign_key(
+                        ForeignKey::create()
+                            .name("fk-friends-friend_source")
+                            .from(crate::schema::friend::Entity, crate::schema::friend::Column::FriendSource)
+                            .to(crate::schema::user::Entity, crate::schema::user::Column::Id),
+                    )
+                    .col(ColumnDef::new(crate::schema::friend::Column::FriendTarget).integer().not_null())
+                    .foreign_key(
+                        ForeignKey::create()
+                            .name("fk-friends-friend_target")
+                            .from(crate::schema::friend::Entity, crate::schema::friend::Column::FriendTarget)
+                            .to(crate::schema::user::Entity, crate::schema::user::Column::Id),
+                    )
+                    .col(ColumnDef::new(crate::schema::friend::Column::State).string().not_null())
+                    .to_owned(),
+            )
+            .await
+    }
+
+    // Define how to rollback this migration: Drop the Friends table.
+    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .drop_table(Table::drop().table(crate::schema::friend::Entity).to_owned())
+            .await
+    }
+}

rc_database/src/migration/mod.rs

@@ -15,6 +15,7 @@ mod m20250918_000001_add_player_variant;
 mod m20251228_000001_create_score_table;
 #[cfg(feature = "factory")]
 mod m20260126_000001_create_factory_vehicle_table;
+mod m20260215_000001_create_friend_table;
 
 pub struct Migrator;
 
@@ -37,6 +38,7 @@ impl MigratorTrait for Migrator {
             Box::new(m20251228_000001_create_score_table::Migration),
             #[cfg(feature = "factory")]
             Box::new(m20260126_000001_create_factory_vehicle_table::Migration),
+            Box::new(m20260215_000001_create_friend_table::Migration),
         ]
     }
 }