Three stores, three importers and three pickers that differ only in their type are one of each (#85)

Refactoring round one: HttpFontStore/HttpSoundStore/HttpTextureStore collapse into a generic
HttpFileStore over a FileStore contract; fontImport/soundImport/textureImport share assetImport
with an ImportKind per sort; ImagePicker/FontPicker/SoundPicker sit on FilePicker and describe
only their row. The group/comment drag logic leaves GraphCanvas for annotationDrag.ts (with its
own unit test), declaredRows.ts replaces the duplicated row build in particles.ts and shaders.ts,
and dead code in font/sound/compile/emission/transform/actions is gone. README: asset list,
check count 958, the two-job CI, the Scenes wiki page.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/core/store/FontStore.ts

@@ -1,26 +1,9 @@
-export interface UploadedFont {
-  /** Content-addressed name in `data/fonts/`: `{sha256}.{ttf|otf|woff|woff2}` (see `isFontFile`). */
-  file: string;
-  /** The name the file was uploaded under, '' when the server knows none. Never a path. */
-  name: string;
-  bytes: number;
-}
-
-/** A typeface the server holds, whether any project references it or not. */
-export interface StoredFont {
-  file: string;
-  name: string;
-  bytes: number;
-  updatedAt: string;
-}
+import type { FileStore, StoredFile, UploadedFile } from './FileStore';
 
 /**
- * Raw bytes, like an image upload: the server derives name and format from the file itself. Unlike
- * an image a font is never re-encoded on the way, so what the server stores is what was picked.
+ * Stored in `data/fonts/` as `{sha256}.{ttf|otf|woff|woff2}`. Unlike an image a font is never
+ * re-encoded on the way, so what the server stores is what was picked.
  */
-export interface FontStore {
-  /** `name` is kept beside the file as its caption; the stored file is always the hash. */
-  upload(bytes: Blob | ArrayBuffer, type: string, name?: string): Promise<UploadedFont>;
-  list(): Promise<StoredFont[]>;
-  delete(file: string): Promise<void>;
-}
+export type UploadedFont = UploadedFile;
+export type StoredFont = StoredFile;
+export type FontStore = FileStore<UploadedFont, StoredFont>;