chore: add assets/attachments DB migration, CLI docs, and lockfile

Add migration 0010 for assets and issue_attachments tables, update CLI
documentation with storage configuration section, and sync pnpm lockfile.

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

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

@@ -71,6 +71,13 @@
       "when": 1771534211029,
       "tag": "0009_fast_jackal",
       "breakpoints": true
+    },
+    {
+      "idx": 10,
+      "version": "7",
+      "when": 1771605173513,
+      "tag": "0010_stale_justin_hammer",
+      "breakpoints": true
     }
   ]
 }