feat: mesh services platform — deploy MCP servers, vaults, scopes

Add the foundation for deploying and managing MCP servers on the VPS
broker, with per-peer credential vaults and visibility scopes.

Architecture:
- One Docker container per mesh with a Node supervisor
- Each MCP server runs as a child process with its own stdio pipe
- claudemesh launch installs native MCP entries in ~/.claude.json
- Mid-session deploys fall back to svc__* dynamic tools + list_changed

New components:
- DB: mesh.service + mesh.vault_entry tables, mesh.skill extensions
- Broker: 19 wire protocol types, 11 message handlers, service catalog
  in hello_ack with scope filtering, service-manager.ts (775 lines)
- CLI: 13 tool definitions, 12 WS client methods, tool call handlers,
  startServiceProxy() for native MCP proxy mode
- Launch: catalog fetch, native MCP entry install, stale sweep, cleanup,
  MCP_TIMEOUT=30s, MAX_MCP_OUTPUT_TOKENS=50k

Security: path sanitization on service names, column whitelist on
upsertService, returning()-based delete checks, vault E2E encryption.

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

apps/broker/src/env.ts

@@ -28,6 +28,9 @@ const envSchema = z.object({
   NEO4J_URL: z.string().default("bolt://neo4j:7687"),
   NEO4J_USER: z.string().default("neo4j"),
   NEO4J_PASSWORD: z.string().default("changeme"),
+  CLAUDEMESH_SERVICES_DIR: z.string().default("/var/claudemesh/services"),
+  MAX_SERVICES_PER_MESH: z.coerce.number().int().positive().default(20),
+  MAX_SERVICE_ZIP_BYTES: z.coerce.number().int().positive().default(50 * 1024 * 1024),
   NODE_ENV: z
     .enum(["development", "production", "test"])
     .default("development"),