fix(auth): add Bearer prefix to PocketBase Authorization header

PocketBase v0.23+ requires 'Bearer <token>' — sending the raw JWT without
the prefix results in 403 'Only superusers can perform this action' on all
collection record endpoints. Fix applied in three places:
- ui/src/lib/server/pocketbase.ts (pbGet, pbPost, pbPatch helpers)
- scraper/internal/storage/pocketbase.go (pbClient.do)
- scripts/pb-init.sh (wget --header in create_collection)

scraper/internal/storage/pocketbase.go

@@ -119,7 +119,7 @@ func (p *pbClient) do(ctx context.Context, method, path string, body interface{}
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("Authorization", tok)
+	req.Header.Set("Authorization", "Bearer "+tok)
 	if body != nil {
 		req.Header.Set("Content-Type", "application/json")
 	}