ModelCraft foundation: workspace, quality gates, FE model, command engine, geometry boundary

A pure-Rust CAE modeling workspace following the SolidCraft conventions:
- modelcraft-model: nodes and elements by label with hostile-input validation
- modelcraft-geometry: SolidCraft's kernel (pinned git dependency) behind our own API;
  tessellation into a face-tagged boundary surface for volume meshing
- modelcraft-engine: CommandSpec registry, Session::execute with rollback and panic guard,
  scripts and a journal
- modelcraft-cli: list commands, run scripts
- xtask: layers (only geometry may use solidcraft-*), assets, licences, tests, wasm, ci
- AGENTS.md, architecture, ADR 0001 (libraries and licences), roadmap, CI

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

deny.toml

@@ -0,0 +1,16 @@
+# Licences are covered by `cargo xtask licences --check`.
+[advisories]
+unmaintained = "all"
+yanked = "warn"
+
+[bans]
+multiple-versions = "warn"
+wildcards = "warn"
+allow-wildcard-paths = true
+
+[sources]
+unknown-registry = "deny"
+unknown-git = "deny"
+allow-registry = ["https://github.com/rust-lang/crates.io-index"]
+# SolidCraft's kernel and its patched truck crates, pinned by rev in Cargo.toml.
+allow-git = ["https://github.com/bherbruck/solidcraft"]