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 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

.github/workflows/ci.yml

@@ -0,0 +1,42 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  ci:
+    name: cargo xtask ci
+    runs-on: ubuntu-24.04
+    timeout-minutes: 60
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt, clippy
+          targets: wasm32-unknown-unknown
+      - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
+      - run: cargo xtask ci
+
+  advisories:
+    name: Dependency advisories and sources
+    runs-on: ubuntu-24.04
+    timeout-minutes: 20
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: dtolnay/rust-toolchain@stable
+      - name: Install cargo-deny
+        run: cargo install cargo-deny --version 0.20.2 --locked
+      - run: cargo deny --locked check --warn unmaintained advisories bans sources