Status LEDs, image model selection, backup restore, provider test, monthly versions

- Sidebar: three status LEDs (server, models, MCP) with an overview popover (/api/status)
- Images: preview stage, purpose-based model choice and reference images
  (Nano Banana Pro edit refines the chosen preview)
- Settings: restore a stored or uploaded backup (staged, applied on restart)
- Provider form: test connection; saving or reloading re-checks the status at once
- opencode Zen/Go: send x-opencode-session with a stable id per conversation
- Releases are named vYYYYMM-NNNNN; scripts/release.sh numbers, tags, builds and publishes
- Fix: backups made in the same second no longer overwrite each other

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server/src/app.rs

@@ -247,11 +247,16 @@ impl App {
         std::fs::rename(&tmp, &self.config_path)?;
         let registry = Registry::build(&cfg).await;
         let mcp_changed = serde_json::to_value(&cfg.mcp)? != serde_json::to_value(&self.config().mcp)?;
+        let providers_changed = serde_json::to_value(&cfg.providers)? != serde_json::to_value(&self.config().providers)?;
         *self.config.write().unwrap() = Arc::new(cfg);
         *self.registry.write().unwrap() = Arc::new(registry);
         if mcp_changed {
             self.clone().start_mcp();
         }
+        // A new key or URL should show its status right away, not at the next 5-minute check.
+        if providers_changed {
+            crate::health::check_all(self).await;
+        }
         Ok(())
     }
 
@@ -263,6 +268,7 @@ impl App {
     pub async fn reload_providers(&self) {
         let registry = Registry::build(&self.config()).await;
         *self.registry.write().unwrap() = Arc::new(registry);
+        crate::health::check_all(self).await;
     }
 
     // --- events ---------------------------------------------------------