chore(svelte): Add manual entries for repo sub pages to development proxy (#64313)

I noticed that non-svelte repo subpages haven't been redirected to the
React app in local development (it works as expected in production).

That's because the proxy doesn't know about them since they are not part
of `knownRoutes`.
We could update the server code to include those routes as well but that
seems heavey handed just to make local development work.

I think in this case it's fine to have manual entries for the handful of
repo subpages that have not been migrated to Svelte yet.

## Test plan

Manual testing.

Author: fkling

client/web-sveltekit/dev/vite-sg-proxy.ts

@@ -33,8 +33,20 @@ export function sgProxy(options: Options): Plugin {
     const contextPlaceholder = '// ---window.context---'
 
     // Additional endpoints that should be proxied to the real Sourcegraph instance.
-    // These are not part of the known routes, but are required for the SvelteKit app to work.
-    const additionalEndpoints = ['/.api/', '/.assets/', '/.auth/']
+    const additionalEndpoints = [
+        // These are not part of the known routes list, but are required for the SvelteKit app to work
+        // in development mode.
+        '^/.api/',
+        '^/.assets/',
+        '^/.auth/',
+        // Repo sub pages are also not part of the known routes list. They are listed here so that we
+        // proxy them to the real Sourcegraph instance, for consistency with the production setup.
+        '/-/raw/',
+        '/-/batch-changes/?',
+        '/-/settings/?',
+        '/-/code-graph/?',
+        '/-/own/?',
+    ]
 
     // Routes known by the server that need to (potentially) be proxied to the real Sourcegraph instance.
     let knownServerRoutes: string[] = []
@@ -91,6 +103,7 @@ export function sgProxy(options: Options): Plugin {
             // from the JS context object. This is used to determine which requests should be proxied to the real Sourcegraph
             // instance.
             try {
+                logger.info(`Fetching JS context from ${options.target}`, { timestamp: true })
                 // The /sign-in endpoint is always available on dotcom and enterprise instances.
                 context = await fetch(`${options.target}/sign-in`)
                     .then(response => response.text())
@@ -125,7 +138,7 @@ export function sgProxy(options: Options): Plugin {
 
             const proxyConfig: Record<string, ProxyOptions> = {
                 // Proxy requests to specific endpoints to a real Sourcegraph instance.
-                [`^(${additionalEndpoints.join('|')})`]: baseOptions,
+                [`${additionalEndpoints.join('|')}`]: baseOptions,
             }
 
             const dynamicOptions: ProxyOptions = {