feat(db): mesh data model — meshes, members, invites, audit log

- pgSchema "mesh" with 4 tables isolating the peer mesh domain
- Enums: visibility, transport, tier, role
- audit_log is metadata-only (E2E encryption enforced at broker/client)
- Cascade on mesh delete, soft-delete via archivedAt/revokedAt

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

packages/shared/package.json

@@ -0,0 +1,36 @@
+{
+  "name": "@turbostarter/shared",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "exports": {
+    "./*": "./src/*/index.ts"
+  },
+  "scripts": {
+    "clean": "git clean -xdf .cache .turbo dist node_modules",
+    "format": "prettier --check . --ignore-path ../../.gitignore",
+    "lint": "eslint",
+    "test": "vitest run",
+    "typecheck": "tsc --noEmit"
+  },
+  "prettier": "@turbostarter/prettier-config",
+  "dependencies": {
+    "lodash": "4.17.21",
+    "pino": "10.1.0",
+    "react": "catalog:react19",
+    "slugify": "1.6.6",
+    "zod": "catalog:"
+  },
+  "devDependencies": {
+    "@turbostarter/eslint-config": "workspace:*",
+    "@turbostarter/prettier-config": "workspace:*",
+    "@turbostarter/tsconfig": "workspace:*",
+    "@turbostarter/vitest-config": "workspace:*",
+    "@types/lodash": "4.17.20",
+    "@types/react": "catalog:react19",
+    "eslint": "catalog:",
+    "prettier": "catalog:",
+    "typescript": "catalog:",
+    "vitest": "catalog:"
+  }
+}