feat: add local auth billing and usage management

lib/server/storage.ts

@@ -146,29 +146,6 @@ export async function importRemoteAssetAsAsset(input: {
   });
 }
 
-export async function saveMaskDataUrl(input: {
-  ownerId: string;
-  dataUrl: string;
-  origin: string;
-  jobHint?: string;
-}): Promise<Asset> {
-  const parsed = parseDataUrl(input.dataUrl);
-  return saveGeneratedAsset({
-    ownerId: input.ownerId,
-    bytes: parsed.bytes,
-    fileName: `mask-${input.jobHint || createId("brush")}.png`,
-    contentType: parsed.contentType,
-    origin: input.origin,
-    source: "edited",
-    capability: "image.inpaint",
-    kind: "mask",
-    tags: ["mask"],
-    metadata: {
-      maskRule: "black keeps original pixels, white repaints selected pixels"
-    }
-  });
-}
-
 export async function readLocalServedFile(area: "uploads" | "generated-results", pathParts: string[]): Promise<{
   bytes: Buffer;
   contentType: string;
@@ -415,15 +392,6 @@ function inferKind(contentType: string): AssetKind {
   return "other";
 }
 
-function parseDataUrl(dataUrl: string): { contentType: string; bytes: Buffer } {
-  const match = dataUrl.match(/^data:([^;,]+);base64,(.+)$/);
-  if (!match) throw new Error("Invalid mask data URL.");
-  return {
-    contentType: match[1],
-    bytes: Buffer.from(match[2], "base64")
-  };
-}
-
 function extensionForContentType(contentType: string): string {
   if (contentType.includes("jpeg") || contentType.includes("jpg")) return ".jpg";
   if (contentType.includes("webp")) return ".webp";