feat(storage): point a full trial account at the upgrade rather than at nothing

Being told "storage limit exceeded" when the limit is the free trial's three
gigabytes is a dead end. The account is not full because it stores a lot; it is
capped because it has not subscribed, and deleting files buys back very little.

The refusal now says which ceiling it is and carries its own error code, so the
toast can offer a link to the billing settings on the trial ceiling and stay
quiet on the paid one, where subscribing changes nothing.

The code had to survive the trip to the toast, which meant the upload helpers
throwing something that carries it rather than a bare Error. Two places were
dropping the server's message on the floor entirely: adding a version reported
"Failed to initialize upload" whatever the server said, and every asset upload
in the pane rewrote its own failure text.

components/video-page/assets-pane.tsx

@@ -3,6 +3,7 @@
 import { memo, useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import * as tus from 'tus-js-client';
 import { toast } from 'sonner';
+import { toastApiError } from '@/lib/client/api-error';
 import {
   Download,
   FileVideo,
@@ -56,6 +57,7 @@ function formatTime(seconds: number): string {
 type UploadAudioResponse = {
   data?: { url?: string; reservationId?: string | null };
   error?: string;
+  code?: string;
 };
 
 function getAudioUploadValidationError(file: Blob): string | null {
@@ -369,10 +371,11 @@ export const AssetsPane = memo(function AssetsPane({
         const uploadPayload = (await uploadRes.json().catch(() => null)) as {
           data?: { url?: string; reservationId?: string | null };
           error?: string;
+          code?: string;
         } | null;
         const uploadedImageUrl = uploadPayload?.data?.url;
         if (!uploadRes.ok || !uploadedImageUrl) {
-          toast.error(`${file.name}: ${uploadPayload?.error || 'Failed to upload image'}`);
+          toastApiError(uploadPayload, 'Failed to upload image', { prefix: file.name });
           return false;
         }
 
@@ -385,7 +388,7 @@ export const AssetsPane = memo(function AssetsPane({
         return !!created;
       } catch (error) {
         console.error('Failed to upload image asset:', error);
-        toast.error(`${file.name}: Failed to upload image`);
+        toastApiError(error, 'Failed to upload image', { prefix: file.name });
         return false;
       }
     },
@@ -523,10 +526,11 @@ export const AssetsPane = memo(function AssetsPane({
             uploadToken: string;
           };
           error?: string;
+          code?: string;
         } | null;
 
         if (!initRes.ok || !initPayload?.data) {
-          toast.error(`${file.name}: ${initPayload?.error || 'Failed to initialize Bunny upload'}`);
+          toastApiError(initPayload, 'Failed to initialize Bunny upload', { prefix: file.name });
           return false;
         }
 
@@ -578,7 +582,7 @@ export const AssetsPane = memo(function AssetsPane({
         return true;
       } catch (error) {
         console.error('Failed to upload Bunny asset:', error);
-        toast.error(`${file.name}: Failed to upload Bunny video`);
+        toastApiError(error, 'Failed to upload Bunny video', { prefix: file.name });
         if (uploadedVideoId && uploadToken) {
           await fetch(`/api/videos/${videoId}/assets/bunny-init`, {
             method: 'DELETE',
@@ -631,7 +635,7 @@ export const AssetsPane = memo(function AssetsPane({
         return true;
       } catch (error) {
         console.error('Failed to upload R2 asset video:', error);
-        toast.error(`${file.name}: Failed to upload video`);
+        toastApiError(error, 'Failed to upload video', { prefix: file.name });
         return false;
       } finally {
         setIsUploadingBunny(false);
@@ -801,12 +805,12 @@ export const AssetsPane = memo(function AssetsPane({
         const uploadPayload = await readUploadAudioResponse(uploadRes);
         const uploadedUrl = uploadPayload?.data?.url;
         if (!uploadRes.ok || !uploadedUrl) {
-          toast.error(
-            `${fileName}: ${
-              uploadPayload?.error ||
-              (uploadRes.status === 413 ? MAX_AUDIO_UPLOAD_SIZE_MESSAGE : null) ||
-              'Failed to upload voice recording'
-            }`
+          toastApiError(
+            uploadPayload,
+            uploadRes.status === 413
+              ? MAX_AUDIO_UPLOAD_SIZE_MESSAGE
+              : 'Failed to upload voice recording',
+            { prefix: fileName }
           );
           return false;
         }
@@ -821,7 +825,7 @@ export const AssetsPane = memo(function AssetsPane({
         return !!created;
       } catch (error) {
         console.error('Failed to upload voice asset:', error);
-        toast.error(`${fileName}: Failed to upload voice recording`);
+        toastApiError(error, 'Failed to upload voice recording', { prefix: fileName });
         return false;
       }
     },