feat: add project workspaces (DB, API, service, and UI)

New project_workspaces table with primary workspace designation.
Full CRUD routes, service with auto-primary promotion on delete,
workspace management UI in project properties panel, and workspace
data included in project/issue ancestor responses.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/db/src/migrations/meta/_journal.json

@@ -127,6 +127,20 @@
       "when": 1771883888199,
       "tag": "0017_tiresome_gabe_jones",
       "breakpoints": true
+    },
+    {
+      "idx": 18,
+      "version": "7",
+      "when": 1771897769629,
+      "tag": "0018_flat_sleepwalker",
+      "breakpoints": true
+    },
+    {
+      "idx": 19,
+      "version": "7",
+      "when": 1772029333401,
+      "tag": "0019_public_victor_mancha",
+      "breakpoints": true
     }
   ]
 }