Puzzle: support history images & partial generation

Allow history-generated image paths to be submitted where Data URLs were previously required and avoid treating partial/result-page generations as blocking the whole draft. Backend: resolve history /generated-* references via resolve_puzzle_reference_image_as_data_url and convert to PuzzleDownloadedImage; add PuzzleDownloadedImage::from_resolved_reference_image; extend draft handling to apply generated level metadata (auto-naming) and normalize generation_status to treat levels with images as ready. API: add shouldAutoNameLevel to action contracts and use it to request/refine generated level names. Spacetime/module and mappers: normalize completed level statuses when saving/reading so result-page background or per-level generation doesn't mask completed drafts. Frontend: expose resolver helpers, only mark a work as generating when no usable cover or ready level exists, keep level controls enabled during UI-background regeneration, and add tests covering history-image submission, auto-naming, and UI-background/partial-generation behaviors.

server-rs/crates/api-server/src/puzzle/vector_engine.rs

@@ -69,6 +69,16 @@ pub(crate) struct PuzzleDownloadedImage {
     pub(crate) bytes: Vec<u8>,
 }
 
+impl PuzzleDownloadedImage {
+    pub(crate) fn from_resolved_reference_image(image: PuzzleResolvedReferenceImage) -> Self {
+        Self {
+            extension: puzzle_mime_to_extension(image.mime_type.as_str()).to_string(),
+            mime_type: normalize_puzzle_downloaded_image_mime_type(image.mime_type.as_str()),
+            bytes: image.bytes,
+        }
+    }
+}
+
 pub(crate) struct ParsedPuzzleImageDataUrl {
     pub(crate) mime_type: String,
     pub(crate) bytes: Vec<u8>,