refactor: change amount to f32

lnvps_db/migrations/20250305215123_amount-float.sql

@@ -0,0 +1,2 @@
+-- Add migration script here
+ALTER TABLE vm_cost_plan MODIFY COLUMN amount float NOT NULL;

lnvps_db/src/model.rs

@@ -179,7 +179,7 @@ pub struct VmCostPlan {
     pub id: u64,
     pub name: String,
     pub created: DateTime<Utc>,
-    pub amount: u64,
+    pub amount: f32,
     pub currency: String,
     pub interval_amount: u64,
     pub interval_type: VmCostPlanIntervalType,

src/api/model.rs

@@ -175,7 +175,7 @@ impl From<lnvps_db::VmCostPlanIntervalType> for ApiVmCostPlanIntervalType {
 pub struct ApiVmCostPlan {
     pub id: u64,
     pub name: String,
-    pub amount: u64,
+    pub amount: f32,
     pub currency: String,
     pub interval_amount: u64,
     pub interval_type: ApiVmCostPlanIntervalType,

src/mocks.rs

@@ -102,7 +102,7 @@ impl Default for MockDb {
                 id: 1,
                 name: "mock".to_string(),
                 created: Utc::now(),
-                amount: 1,
+                amount: 1f32,
                 currency: "EUR".to_string(),
                 interval_amount: 1,
                 interval_type: VmCostPlanIntervalType::Month,

src/provisioner/lnvps.rs

@@ -321,7 +321,7 @@ impl LNVpsProvisioner {
             bail!("No exchange rate found")
         };
 
-        let cost_btc = cost_plan.amount as f32 / rate;
+        let cost_btc = cost_plan.amount / rate;
         let cost_msat = (cost_btc as f64 * BTC_SATS) as u64 * 1000;
         info!("Creating invoice for {vm_id} for {} sats", cost_msat / 1000);
         let invoice = self