docs(plugins): version breaking API guides (#4245)

Keep stable v0.7 guidance available while the client-entry layout is previewed for v0.8. Existing reference and migration URLs redirect to the release that owns their content.

packages/server/src/server/plugins/runtime.posix.test.ts

@@ -507,7 +507,7 @@ export default function contribute(plugin: unknown) {
       "Plugin entry split is required",
     );
     await expect(runtime.startPlugin("legacy", directory)).rejects.toThrow(
-      "https://paseo.sh/docs/plugins/migration",
+      "https://paseo.sh/docs/plugins/v0.8/migration",
     );
   });
 

packages/server/src/server/plugins/runtime.ts

@@ -207,7 +207,7 @@ async function resolveEntryPaths(directory: string): Promise<{
   const legacyEntry = await findEntry(directory, ["index.ts", "index.tsx"]);
   if (legacyEntry) {
     throw new Error(
-      "Plugin entry split is required: migrate index.ts to index.client.tsx and/or index.server.ts. See https://paseo.sh/docs/plugins/migration",
+      "Plugin entry split is required: migrate index.ts to index.client.tsx and/or index.server.ts. See https://paseo.sh/docs/plugins/v0.8/migration",
     );
   }
   throw new Error(