Add explicit return types to image response routes

src/app/(static)/home-image/route.tsx

@@ -10,7 +10,7 @@ import { ImageResponse } from '@vercel/og';
 
 export const runtime = 'edge';
 
-export async function GET(request: Request) {
+export async function GET(request: Request): Promise<ImageResponse> {
   const photos = await getPhotos(
     undefined,
     MAX_PHOTOS_TO_SHOW_HOME,

src/app/(static)/p/[photoId]/image/route.tsx

@@ -8,7 +8,10 @@ import { ImageResponse } from '@vercel/og';
 
 export const runtime = 'edge';
 
-export async function GET(request: Request, context: any) {
+export async function GET(
+  request: Request,
+  context: any,
+): Promise<ImageResponse | null> {
   const photo = await getPhoto(context.params.photoId);
 
   const {

src/app/(static)/t/[tag]/image/route.tsx

@@ -11,7 +11,10 @@ import { ImageResponse } from '@vercel/og';
 
 export const runtime = 'edge';
 
-export async function GET(request: Request, context: any) {
+export async function GET(
+  request: Request,
+  context: any,
+): Promise<ImageResponse> {
   const photos = await getPhotos(
     undefined,
     MAX_PHOTOS_TO_SHOW_PER_TAG,

src/app/(static)/template-image-tight/route.tsx

@@ -12,7 +12,7 @@ import { ImageResponse } from '@vercel/og';
 
 export const runtime = 'edge';
 
-export async function GET(request: Request) {
+export async function GET(request: Request): Promise<ImageResponse> {
   const photos = await getPhotos('priority', MAX_PHOTOS_TO_SHOW_TEMPLATE_TIGHT);
 
   const {

src/app/(static)/template-image/route.tsx

@@ -12,7 +12,7 @@ import { ImageResponse } from '@vercel/og';
 
 export const runtime = 'edge';
 
-export async function GET(request: Request) {
+export async function GET(request: Request): Promise<ImageResponse> {
   const photos = await getPhotos('priority', MAX_PHOTOS_TO_SHOW_TEMPLATE);
   const {
     fontFamily,