Return correct HTTP status for disallowed HTTP methods

Make sure that we return the correct HTTP status for disallowed
HTTP methods:

- For pages that do not exist, return 404.
- For pages that do exist but do not support the requested method,
  return 405.

A fact of life on the Internet is that public sites are constantly
being probed for vulnerabilities or misconfigurations of common
frameworks. These requests often attempt to POST or PUT to
irrelevant endpoints. Before this patch, we were logging something
like this for each such request:

```
2024-12-08T13:52:31.557Z	48395885-e0a7-4cda-a750-3d5267bb20d1	ERROR	Error: You made a POST request to "/wp-admin/admin-ajax.php" but did not provide an `action` for route "routes/$", so there is no way to handle the request.
    at sa (/var/task/index.cjs:49:10806)
    at u (/var/task/index.cjs:48:47306)
    at c (/var/task/index.cjs:48:46995)
    at Object.s [as query] (/var/task/index.cjs:48:46027)
    at Nvt (/var/task/index.cjs:64:17420)
    at /var/task/index.cjs:64:15716
    at /var/task/index.cjs:137:7577
    at Runtime.hOr [as handler] (/var/task/index.cjs:2326:74163)
2024-12-08T13:52:31.616Z	48395885-e0a7-4cda-a750-3d5267bb20d1	ERROR	Error: Invariant failed
    at Ln (/var/task/index.cjs:318:39742)
    at lm (/var/task/index.cjs:340:1264)
    at O2 (/var/task/index.cjs:340:1930)
    at Blr (/var/task/index.cjs:340:2261)
    at y8e (/var/task/index.cjs:192:3805)
    at rZ (/var/task/index.cjs:192:4617)
    at gu (/var/task/index.cjs:192:7257)
    at rZ (/var/task/index.cjs:192:6651)
    at gu (/var/task/index.cjs:192:7257)
    at rZ (/var/task/index.cjs:192:6651)
2024-12-08T13:52:31.619Z	48395885-e0a7-4cda-a750-3d5267bb20d1	ERROR	Error: Invariant failed
    at Ln (/var/task/index.cjs:318:39742)
    at lm (/var/task/index.cjs:340:1264)
    at O2 (/var/task/index.cjs:340:1930)
    at Blr (/var/task/index.cjs:340:2261)
    at y8e (/var/task/index.cjs:192:3805)
    at rZ (/var/task/index.cjs:192:4617)
    at gu (/var/task/index.cjs:192:7257)
    at rZ (/var/task/index.cjs:192:6651)
    at gu (/var/task/index.cjs:192:7257)
    at rZ (/var/task/index.cjs:192:6651)
```

Don't treat these as server errors and don't log them. Do return
the correct HTTP status.

app/components/CircularsEmailAddress.tsx

@@ -9,7 +9,7 @@ import { useHostname } from '~/root'
 
 export function useCircularsEmailAddress() {
   let hostname = useHostname()
-  if (!hostname.endsWith('gcn.nasa.gov')) hostname = 'test.gcn.nasa.gov'
+  if (!hostname?.endsWith('gcn.nasa.gov')) hostname = 'test.gcn.nasa.gov'
   return `circulars@${hostname}`
 }
 

app/components/NoticeFormat.tsx

@@ -18,7 +18,7 @@ export function NoticeFormatInput({
   onChange,
 }: {
   name: string
-  showJson: boolean
+  showJson?: boolean
   value?: NoticeFormat
   onChange?: (arg: NoticeFormat) => void
 }) {

app/lib/utils.ts

@@ -45,7 +45,7 @@ export function getFormDataString(formData: FormData, key: string) {
   }
 }
 
-export function getEnvBannerHeaderAndDescription(hostname: string) {
+export function getEnvBannerHeaderAndDescription(hostname?: string) {
   const production_hostname = 'gcn.nasa.gov'
   let heading, description
   if (hostname === `dev.${production_hostname}`) {

app/root.tsx

@@ -138,39 +138,31 @@ export function shouldRevalidate() {
 }
 
 function useLoaderDataRoot() {
-  const result = useRouteLoaderData<typeof loader>('root')
-  invariant(result)
-  return result
+  return useRouteLoaderData<typeof loader>('root')
 }
 
 export function useUserIdp() {
-  const { idp } = useLoaderDataRoot()
-  return idp
+  return useLoaderDataRoot()?.idp
 }
 
 export function useEmail() {
-  const { email } = useLoaderDataRoot()
-  return email
+  return useLoaderDataRoot()?.email
 }
 
 export function useName() {
-  const { name } = useLoaderDataRoot()
-  return name
+  return useLoaderDataRoot()?.name
 }
 
 export function useModStatus() {
-  const { userIsMod } = useLoaderDataRoot()
-  return userIsMod
+  return useLoaderDataRoot()?.userIsMod
 }
 
 export function useSubmitterStatus() {
-  const { userIsVerifiedSubmitter } = useLoaderDataRoot()
-  return userIsVerifiedSubmitter
+  return useLoaderDataRoot()?.userIsVerifiedSubmitter
 }
 
 export function useRecaptchaSiteKey() {
-  const { recaptchaSiteKey } = useLoaderDataRoot()
-  return recaptchaSiteKey
+  return useLoaderDataRoot()?.recaptchaSiteKey
 }
 
 /**
@@ -183,7 +175,7 @@ export function useRecaptchaSiteKey() {
  */
 export function useFeature(feature: string) {
   const featureUppercase = feature.toUpperCase()
-  return useLoaderDataRoot().features.includes(featureUppercase)
+  return useLoaderDataRoot()?.features.includes(featureUppercase)
 }
 
 export function WithFeature({
@@ -195,8 +187,13 @@ export function WithFeature({
   return <>{useFeature(Object.keys(features)[0]) && children}</>
 }
 
+export function useOrigin() {
+  return useLoaderDataRoot()?.origin
+}
+
 export function useUrl() {
-  const { origin } = useLoaderDataRoot()
+  const origin = useOrigin()
+  invariant(origin)
   const { pathname, search, hash } = useLocation()
   const url = new URL(origin)
   url.pathname = pathname
@@ -205,12 +202,9 @@ export function useUrl() {
   return url.toString()
 }
 
-export function useOrigin() {
-  return useLoaderDataRoot().origin
-}
-
 export function useHostname() {
-  return new URL(useLoaderDataRoot().origin).hostname
+  const origin = useOrigin()
+  if (origin) return new URL(origin).hostname
 }
 
 export function useDomain() {

app/routes/$.ts

@@ -1,5 +1,5 @@
 import type { SEOHandle } from '@nasa-gcn/remix-seo'
-import type { LoaderFunction } from '@remix-run/node'
+import type { ActionFunction, LoaderFunction } from '@remix-run/node'
 
 import type { BreadcrumbHandle } from '~/root/Title'
 
@@ -12,4 +12,8 @@ export const loader: LoaderFunction = function () {
   throw new Response(null, { status: 404 })
 }
 
+export const action: ActionFunction = function () {
+  throw new Response(null, { status: 404 })
+}
+
 export default function () {}