v0.2.1

Replace hardcoded "0.2.0" version literal in mcp-channel-server constructor with (app-version) read from (sigil meta). Same for name: — now (app-name). package.sgl version: field is the single source of truth.

Requires sigil-build v0.14.4 + sigil-lib v0.14.2 (already shipped) so the bundle's MANIFEST.sgl carries app-version and meta.c picks it up at runtime. Verified: ./build/release/bin/minder --version reports "minder 0.2.1 (sigil 0.14.3)" and the MCP serverInfo block will reflect the same number going forward.