Implement Workstream J: Org procedures (backend)

Add complete organization management procedures:
- orgs.list, create, get, update, delete, leave
- orgs.members.list, updateRole, remove
- orgs.invites.list, create, cancel, accept
- orgs.sites.list

Key features:
- Role-based access control (owner > admin > member)
- Transaction-protected owner count checks to prevent race conditions
- Privilege escalation prevention (only owners can invite owners)
- Graceful constraint violation handling with friendly error messages
- Email sending for org invitations

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api-server/src/procedures/orgs/index.ts

@@ -0,0 +1,14 @@
+/**
+ * Org procedures - organization management
+ */
+
+export { orgsCreate, orgsGet, orgsList } from "./basic.js";
+export {
+  invitesAccept,
+  invitesCancel,
+  invitesCreate,
+  invitesList,
+} from "./invites.js";
+export { orgsDelete, orgsLeave, orgsUpdate } from "./management.js";
+export { membersList, membersRemove, membersUpdateRole } from "./members.js";
+export { sitesList } from "./sites.js";