feat(workspaces): scaffold feature

Scaffold the workspaces feature package via pnpm turbo gen feature
(single Workspace entity, getWorkspace use case) and hand-wire the
aggregators: bindAll dispatcher (web-next), core-api app router, and
workspace deps. Release-please registration reverted per the root-only
versioning policy (AGENTS.md, ADR-027 retrofit). Pinned @trpc/server
to the repo-wide 11.16.0 resolution so instanceof TRPCError checks
share one module instance.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016j8z4VHjedXDTjEDNg7qHK

packages/core-api/package.json

@@ -17,6 +17,7 @@
     "@repo/core-consent": "workspace:*",
     "@repo/core-dsr": "workspace:*",
     "@repo/core-shared": "workspace:*",
+    "@repo/workspaces": "workspace:*",
     "@trpc/server": "^11.0.0"
   },
   "devDependencies": {

packages/core-api/src/root.ts

@@ -1,10 +1,12 @@
 import { router } from "@repo/core-shared/trpc/init";
 import { authRouter } from "@repo/auth/api";
+import { workspacesRouter } from "@repo/workspaces/api";
 import { dsrRouter } from "@repo/core-dsr";
 import { consentRouter } from "@repo/core-consent";
 
 export const appRouter = router({
   auth: authRouter,
+  workspaces: workspacesRouter,
   // gen:routers — optional-core routers composed below
   dsr: dsrRouter,
   consent: consentRouter,