remove Python from Docker: use Rust CLI for config generation

crates/plano-cli/src/commands/render_config.rs

@@ -0,0 +1,33 @@
+use std::path::Path;
+
+use anyhow::Result;
+
+use crate::config;
+
+/// Render config files for Docker/supervisord use.
+/// Reads paths from environment variables (matching the old Python config_generator).
+pub async fn run() -> Result<()> {
+    let config_file =
+        std::env::var("PLANO_CONFIG_FILE").unwrap_or_else(|_| "/app/plano_config.yaml".to_string());
+    let schema_file = std::env::var("PLANO_CONFIG_SCHEMA_FILE")
+        .unwrap_or_else(|_| "plano_config_schema.yaml".to_string());
+    let template_root = std::env::var("TEMPLATE_ROOT").unwrap_or_else(|_| "./".to_string());
+    let template_file = std::env::var("ENVOY_CONFIG_TEMPLATE_FILE")
+        .unwrap_or_else(|_| "envoy.template.yaml".to_string());
+    let config_rendered = std::env::var("PLANO_CONFIG_FILE_RENDERED")
+        .unwrap_or_else(|_| "/app/plano_config_rendered.yaml".to_string());
+    let envoy_rendered = std::env::var("ENVOY_CONFIG_FILE_RENDERED")
+        .unwrap_or_else(|_| "/etc/envoy/envoy.yaml".to_string());
+
+    let template_path = Path::new(&template_root).join(&template_file);
+
+    config::validate_and_render(
+        Path::new(&config_file),
+        Path::new(&schema_file),
+        &template_path,
+        Path::new(&envoy_rendered),
+        Path::new(&config_rendered),
+    )?;
+
+    Ok(())
+}