collab: Add support for subscribing to Zed Pro trials (#28812)

This PR adds support for subscribing to Zed Pro trials (and then
upgrading from a trial to Zed Pro).

Release Notes:

- N/A

crates/collab/src/stripe_billing.rs

@@ -1,16 +1,16 @@
 use std::sync::Arc;
 
 use crate::{Cents, Result, llm};
-use anyhow::{Context as _, anyhow};
+use anyhow::Context as _;
 use chrono::{Datelike, Utc};
 use collections::HashMap;
 use serde::{Deserialize, Serialize};
+use stripe::PriceId;
 use tokio::sync::RwLock;
 
 pub struct StripeBilling {
     state: RwLock<StripeBillingState>,
     client: Arc<stripe::Client>,
-    zed_pro_price_id: Option<String>,
 }
 
 #[derive(Default)]
@@ -32,11 +32,10 @@ struct StripeBillingPrice {
 }
 
 impl StripeBilling {
-    pub fn new(client: Arc<stripe::Client>, zed_pro_price_id: Option<String>) -> Self {
+    pub fn new(client: Arc<stripe::Client>) -> Self {
         Self {
             client,
             state: RwLock::default(),
-            zed_pro_price_id,
         }
     }
 
@@ -385,23 +384,19 @@ impl StripeBilling {
         Ok(session.url.context("no checkout session URL")?)
     }
 
-    pub async fn checkout_with_zed_pro(
+    pub async fn checkout_with_price(
         &self,
+        price_id: PriceId,
         customer_id: stripe::CustomerId,
         github_login: &str,
         success_url: &str,
     ) -> Result<String> {
-        let zed_pro_price_id = self
-            .zed_pro_price_id
-            .as_ref()
-            .ok_or_else(|| anyhow!("Zed Pro price ID not set"))?;
-
         let mut params = stripe::CreateCheckoutSession::new();
         params.mode = Some(stripe::CheckoutSessionMode::Subscription);
         params.customer = Some(customer_id);
         params.client_reference_id = Some(github_login);
         params.line_items = Some(vec![stripe::CreateCheckoutSessionLineItems {
-            price: Some(zed_pro_price_id.clone()),
+            price: Some(price_id.to_string()),
             quantity: Some(1),
             ..Default::default()
         }]);