chore: add cross-platform clippy recipes to justfile

Add `just lint-linux` and `just lint-windows` for cross-compiling clippy
checks via cargo-zigbuild and cargo-xwin, and document them in CLAUDE.md.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: branchseer

CLAUDE.md

@@ -13,6 +13,8 @@ just fmt           # Format code (cargo fmt, cargo shear, dprint)
 just check         # Check compilation with all features
 just test          # Run all tests
 just lint          # Clippy linting
+just lint-linux    # Cross-clippy for Linux (requires cargo-zigbuild)
+just lint-windows  # Cross-clippy for Windows (requires cargo-xwin)
 just doc           # Documentation generation
 ```
 
@@ -88,6 +90,16 @@ Tasks are defined in `vite-task.json`:
    - With `-r/--recursive`: runs task across all packages in dependency order
    - With `-t/--transitive`: runs task in current package and its dependencies
 
+## Cross-Platform Linting
+
+After major changes (especially to `fspy*` or platform-specific crates), run cross-platform clippy before pushing:
+
+```bash
+just lint          # native (host platform)
+just lint-linux    # Linux via cargo-zigbuild
+just lint-windows  # Windows via cargo-xwin
+```
+
 ## Code Constraints
 
 These patterns are enforced by `.clippy.toml`:

justfile

@@ -41,6 +41,12 @@ test:
 lint:
   cargo clippy --workspace --all-targets --all-features -- --deny warnings
 
+lint-linux:
+  cargo-zigbuild clippy --workspace --all-targets --all-features --target x86_64-unknown-linux-gnu -- --deny warnings
+
+lint-windows:
+  cargo-xwin clippy --workspace --all-targets --all-features --target x86_64-pc-windows-msvc -- --deny warnings
+
 [unix]
 doc:
   RUSTDOCFLAGS='-D warnings' cargo doc --no-deps --document-private-items