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/config.rs

@@ -193,6 +193,15 @@ pub struct ImageModel {
     /// Extra request fields sent as-is.
     #[serde(default, skip_serializing_if = "serde_json::Map::is_empty")]
     pub options: serde_json::Map<String, serde_json::Value>,
+    /// "preview" (cheap drafts) or "final" (best quality). Known fal.ai models have defaults.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub stage: Option<String>,
+    /// What the model is good at: photo, illustration, text, design.
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub good_for: Vec<String>,
+    /// Request field for reference images (e.g. "image_urls"); set for models that refine an image.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub reference_param: Option<String>,
 }
 
 impl Default for ImagesConfig {