fix(plugins): render template function config values before plugins see them (#608)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

crates/yaak-commands/src/render.rs

@@ -1,12 +1,19 @@
 //! Rendering a template against an environment chain.
 //!
 //! The variables come from the chain, the functions come from the host's
-//! template callback. Neither of these knows which host it is running under —
-//! that is the whole point of taking the callback as a parameter.
+//! template callback. `render_template` and `render_json_value` know nothing
+//! about which host they run under — that is the whole point of taking the
+//! callback as a parameter. `render_form_values` sits one level up: resolving
+//! the chain a model sits in is an ordinary database read, so it takes the
+//! host and does that read before rendering.
 
+use crate::error::{Error, Result};
+use crate::host::PluginHost;
 use serde_json::Value;
-use yaak_models::models::Environment;
+use std::collections::HashMap;
+use yaak_models::models::{AnyModel, Environment};
 use yaak_models::render::make_vars_hashmap;
+use yaak_plugins::events::{JsonPrimitive, RenderPurpose};
 use yaak_templates::{RenderOptions, TemplateCallback, parse_and_render, render_json_value_raw};
 
 pub async fn render_template<T: TemplateCallback>(
@@ -28,3 +35,40 @@ pub async fn render_json_value<T: TemplateCallback>(
     let vars = &make_vars_hashmap(environment_chain);
     render_json_value_raw(value, vars, cb, opt).await
 }
+
+/// Render a config form's values against the environment chain the model sits in.
+///
+/// The chain depends on where the model lives — a request inherits through its
+/// folder, a workspace has only its own — so the model is what decides which
+/// variables are in scope.
+pub(crate) async fn render_form_values<H: PluginHost>(
+    host: &H,
+    model: &AnyModel,
+    environment_id: Option<&str>,
+    values: HashMap<String, JsonPrimitive>,
+    purpose: RenderPurpose,
+    options: &RenderOptions,
+) -> Result<HashMap<String, JsonPrimitive>> {
+    let (workspace_id, folder_id) = match model {
+        AnyModel::HttpRequest(r) => (r.workspace_id.clone(), r.folder_id.clone()),
+        AnyModel::GrpcRequest(r) => (r.workspace_id.clone(), r.folder_id.clone()),
+        AnyModel::WebsocketRequest(r) => (r.workspace_id.clone(), r.folder_id.clone()),
+        AnyModel::Folder(f) => (f.workspace_id.clone(), f.folder_id.clone()),
+        AnyModel::Workspace(w) => (w.id.clone(), None),
+        other => {
+            return Err(Error::Generic(format!(
+                "Cannot resolve environments for a {}",
+                other.model()
+            )));
+        }
+    };
+
+    let environment_chain =
+        host.db().resolve_environments(&workspace_id, folder_id.as_deref(), environment_id)?;
+
+    let cb = host.template_callback(purpose);
+    let rendered =
+        render_json_value(serde_json::to_value(&values)?, environment_chain, &cb, options).await?;
+
+    Ok(serde_json::from_value(rendered)?)
+}