init deeplink redirects (#804)

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Fix for a lot of the deep links that are causing 404 errors from old
docs.

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----

> [!IMPORTANT]
> Adds dynamic redirection for documentation routes in multiple
sections, redirecting to the correct page or an overview, with special
handling for REST API routes.
> 
>   - **Behavior**:
> - Adds dynamic redirection for documentation routes in `js`, `next`,
`python`, `react`, and `rest-api` sections.
> - Redirects to the correct documentation page or an overview if the
page doesn't exist.
>     - For `rest-api`, redirects to `/api` instead of `/docs`.
>   - **Files**:
> - `route.ts` in `js`, `next`, `python`, `react`, and `rest-api`
sections handle the redirection logic.
> - Uses `source.getPage()` or `apiSource.getPage()` to check page
existence.
> 
> <sup>This description was created by </sup>[<img alt="Ellipsis"
src="https://img.shields.io/badge/Ellipsis-blue?color=175173">](https://www.ellipsis.dev?ref=stack-auth%2Fstack-auth&utm_source=github&utm_medium=referral)<sup>
for 50c4b592a4. You can
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summary. It will automatically update as commits are pushed.</sup>

----


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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added dynamic redirection for documentation routes in JavaScript,
Next.js, Python, React, and REST API sections. Users are now
automatically redirected to the correct documentation page if it exists,
or receive a 404 not found response if the page is missing. This
improves navigation and error handling for documentation URLs.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Konsti Wohlwend <n2d4xc@gmail.com>

docs/src/app/js/[...path]/route.ts

@@ -0,0 +1,31 @@
+import { source } from 'lib/source';
+import { notFound, redirect } from 'next/navigation';
+import { NextRequest } from 'next/server';
+
+export function GET(request: NextRequest) {
+  const pathname = new URL(request.url).pathname;
+
+  // Ensure we have the correct target path without double prefixes using proper URL construction
+  let targetPath: string;
+  if (pathname.startsWith('/docs')) {
+    targetPath = pathname;
+  } else {
+    // Remove leading slash and use as relative path to properly construct /docs prefix
+    targetPath = new URL(pathname.substring(1), 'file:///docs/').pathname;
+  }
+
+  // Extract slug by removing any '/docs' prefix and splitting by '/'
+  const cleanPath = pathname.startsWith('/docs') ? pathname.substring(5) : pathname;
+  const slug = cleanPath.substring(1).split('/').filter(Boolean);
+
+  // Check if the target page exists
+  const page = source.getPage(slug);
+
+  if (page) {
+    // Page exists, redirect to the full path
+    return redirect(targetPath);
+  } else {
+    // Page doesn't exist, return 404
+    return notFound();
+  }
+}

docs/src/app/next/[...path]/route.ts

@@ -0,0 +1,31 @@
+import { source } from 'lib/source';
+import { notFound, redirect } from 'next/navigation';
+import { NextRequest } from 'next/server';
+
+export function GET(request: NextRequest) {
+  const pathname = new URL(request.url).pathname;
+
+  // Ensure we have the correct target path without double prefixes using proper URL construction
+  let targetPath: string;
+  if (pathname.startsWith('/docs')) {
+    targetPath = pathname;
+  } else {
+    // Remove leading slash and use as relative path to properly construct /docs prefix
+    targetPath = new URL(pathname.substring(1), 'file:///docs/').pathname;
+  }
+
+  // Extract slug by removing any '/docs' prefix and splitting by '/'
+  const cleanPath = pathname.startsWith('/docs') ? pathname.substring(5) : pathname;
+  const slug = cleanPath.substring(1).split('/').filter(Boolean);
+
+  // Check if the target page exists
+  const page = source.getPage(slug);
+
+  if (page) {
+    // Page exists, redirect to the full path
+    return redirect(targetPath);
+  } else {
+    // Page doesn't exist, redirect to overview
+    return notFound();
+  }
+}

docs/src/app/python/[...path]/route.ts

@@ -0,0 +1,31 @@
+import { source } from 'lib/source';
+import { notFound, redirect } from 'next/navigation';
+import { NextRequest } from 'next/server';
+
+export function GET(request: NextRequest) {
+  const pathname = new URL(request.url).pathname;
+
+  // Ensure we have the correct target path without double prefixes using proper URL construction
+  let targetPath: string;
+  if (pathname.startsWith('/docs')) {
+    targetPath = pathname;
+  } else {
+    // Remove leading slash and use as relative path to properly construct /docs prefix
+    targetPath = new URL(pathname.substring(1), 'file:///docs/').pathname;
+  }
+
+  // Extract slug by removing any '/docs' prefix and splitting by '/'
+  const cleanPath = pathname.startsWith('/docs') ? pathname.substring(5) : pathname;
+  const slug = cleanPath.substring(1).split('/').filter(Boolean);
+
+  // Check if the target page exists
+  const page = source.getPage(slug);
+
+  if (page) {
+    // Page exists, redirect to the full path
+    return redirect(targetPath);
+  } else {
+    // Page doesn't exist, redirect to overview
+    return notFound();
+  }
+}

docs/src/app/react/[...path]/route.ts

@@ -0,0 +1,31 @@
+import { source } from 'lib/source';
+import { notFound, redirect } from 'next/navigation';
+import { NextRequest } from 'next/server';
+
+export function GET(request: NextRequest) {
+  const pathname = new URL(request.url).pathname;
+
+  // Ensure we have the correct target path without double prefixes using proper URL construction
+  let targetPath: string;
+  if (pathname.startsWith('/docs')) {
+    targetPath = pathname;
+  } else {
+    // Remove leading slash and use as relative path to properly construct /docs prefix
+    targetPath = new URL(pathname.substring(1), 'file:///docs/').pathname;
+  }
+
+  // Extract slug by removing any '/docs' prefix and splitting by '/'
+  const cleanPath = pathname.startsWith('/docs') ? pathname.substring(5) : pathname;
+  const slug = cleanPath.substring(1).split('/').filter(Boolean);
+
+  // Check if the target page exists
+  const page = source.getPage(slug);
+
+  if (page) {
+    // Page exists, redirect to the full path
+    return redirect(targetPath);
+  } else {
+    // Page doesn't exist, redirect to overview
+    return notFound();
+  }
+}

docs/src/app/rest-api/[...path]/route.ts

@@ -0,0 +1,31 @@
+import { apiSource } from 'lib/source';
+import { notFound, redirect } from 'next/navigation';
+import { NextRequest } from 'next/server';
+
+export function GET(request: NextRequest) {
+  const pathname = new URL(request.url).pathname;
+
+  // For rest-api, we redirect to /api not /docs using proper URL construction
+  let targetPath: string;
+  if (pathname.startsWith('/api')) {
+    targetPath = pathname;
+  } else {
+    // Remove leading slash and use as relative path to properly construct /api prefix
+    targetPath = new URL(pathname.substring(1), 'file:///api/').pathname;
+  }
+
+  // Extract slug by removing any '/api' prefix and splitting by '/'
+  const cleanPath = pathname.startsWith('/api') ? pathname.substring(4) : pathname;
+  const slug = cleanPath.substring(1).split('/').filter(Boolean);
+
+  // Check if the target page exists using apiSource for API docs
+  const page = apiSource.getPage(slug);
+
+  if (page) {
+    // Page exists, redirect to the full path
+    return redirect(targetPath);
+  } else {
+    // Page doesn't exist, redirect to overview
+    return notFound();
+  }
+}