feat!: remove v1 route convention codepaths (#5649)

Signed-off-by: Logan McAnsh <logan@mcan.sh>

.changeset/remove-v1-routes.md

@@ -0,0 +1,9 @@
+---
+"remix": major
+"@remix-run/dev": major
+"@remix-run/react": major
+"@remix-run/server-runtime": major
+"@remix-run/testing": major
+---
+
+remove v1 route convention codepaths

docs/file-conventions/route-files-v2.md → docs/file-conventions/route-files.md

@@ -1,22 +1,8 @@
 ---
-title: Route File Naming (v2)
+title: Route File Naming
 ---
 
-# Route File Naming (v2)
-
-You can opt-in to the new route file naming convention with a future flag in Remix config. It will be the default behavior in the future when v2 ships. For background on this change, [see the RFC][flatroutes-rfc].
-
-```js filename=remix.config.js
-module.exports = {
-  future: {
-    v2_routeConvention: true,
-  },
-};
-```
-
-We encourage you to make this change early so upgrading is easy. We'll be providing a helper function to use the old convention in v2 if you prefer it.
-
----
+# Route File Naming
 
 While you can configure routes in [remix.config.js][remix-config], most routes are created with this file system convention. Add a file, get a route.
 

docs/guides/data-loading.md

@@ -146,7 +146,7 @@ export { db };
 
 And then your routes can import it and make queries against it:
 
-```tsx filename=app/routes/products/$categoryId.tsx
+```tsx filename=app/routes/products.$categoryId.tsx
 import type { LoaderArgs } from "@remix-run/node"; // or cloudflare/deno
 import { json } from "@remix-run/node"; // or cloudflare/deno
 import { useLoaderData } from "@remix-run/react";
@@ -176,7 +176,7 @@ export default function ProductCategory() {
 
 If you are using TypeScript, you can use type inference to use Prisma Client generated types when calling `useLoaderData`. This allows better type safety and intellisense when writing code that uses the loaded data.
 
-```tsx filename=app/routes/products/$productId.tsx
+```tsx filename=app/routes/products.$productId.tsx
 import type { LoaderArgs } from "@remix-run/node"; // or cloudflare/deno
 import { json } from "@remix-run/node"; // or cloudflare/deno
 import { useLoaderData } from "@remix-run/react";
@@ -324,7 +324,7 @@ Sometimes you need to read and change the search params from your component inst
 
 Perhaps the most common way to set search params is letting the user control them with a form:
 
-```tsx filename=app/routes/products/shoes.tsx lines=[8,9,16,17]
+```tsx filename=app/routes/products.shoes.tsx lines=[8,9,16,17]
 export default function ProductFilters() {
   return (
     <Form method="get">

docs/guides/data-writes.md

@@ -147,7 +147,7 @@ Whether you use `<form>` or `<Form>` though, you write the very same code. You c
 
 Let's start with our project form from earlier but make it usable:
 
-Let's say you've got the route `app/routes/projects/new.js` with this form in it:
+Let's say you've got the route `app/routes/projects.new.js` with this form in it:
 
 ```tsx
 export default function NewProject() {