v0.9.0 MCP proxy starter

Adds a dependency-free MCP proxy starter for gating JSON-RPC-style MCP tool calls before forwarding to an upstream server.\n\nHighlights:\n- New examples/mcp-proxy-starter.mjs starter\n- Gates tools/call requests before forwarding\n- Blocks dangerous shell commands before the upstream MCP server sees them\n- Queues side-effecting tool calls until approval creates an ApprovedCommand\n- New npm run example:mcp-proxy command\n- Tests for read-only forwarding, queued approval, blocked calls, and the demo path\n\nTry it with:\nsh\nnpm install @pallattu/aeg-intent-gate\nnpm run example:mcp-proxy\n