feat(api): mesh user router — create, list, invite, archive, leave

New /my/* Hono router scoped by session.user.id. User can only see meshes
they own OR have a non-revoked meshMember row for. All 7 endpoints guard
authz at the query level (ownerUserId = userId OR EXISTS membership).

- GET /my/meshes — paginated list with myRole, isOwner, memberCount
- POST /my/meshes — create mesh (slug collision check, returns id + slug)
- GET /my/meshes/:id — detail (mesh + members + invites)
- POST /my/meshes/:id/invites — generate ic://join/<base64url(JSON)> link.
  Matches apps/cli/src/invite/parse.ts format exactly. mesh_root_key is a
  deterministic sha256(mesh.id:slug) placeholder until Step 18 ed25519
  signing lands.
- POST /my/meshes/:id/archive — owner-only
- POST /my/meshes/:id/leave — member self-removal (sets revokedAt)
- GET /my/invites — list invites this user has issued

Schemas live in packages/api/src/schema/mesh-user.ts. All enums mirror
the DB enums from packages/db/src/schema/mesh.ts.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/api/src/schema/index.ts

@@ -1,3 +1,4 @@
 export * from "./admin";
 export * from "./mesh-admin";
+export * from "./mesh-user";
 export * from "./organization";