When working on Rust code in compiler/crates/:

• Follow patterns from compiler/docs/rust-port/rust-port-architecture.md
• Use arenas + copyable IDs instead of shared references: IdentifierId, ScopeId, FunctionId, TypeId
• Pass env: &mut Environment separately from func: &mut HirFunction
• Use two-phase collect/apply when you can't mutate through stored references
• Run bash compiler/scripts/test-babel-ast.sh to test AST round-tripping
• Use /port-pass <name> when porting a new compiler pass
• Use /compiler-verify before committing to run both Rust and TS tests
• Keep Rust code structurally close to the TypeScript (~85-95% correspondence)

Before declaring work complete on a plan doc:

• Re-read the original user prompt to ensure all requested steps are done
• Check the plan doc for any "Remaining Work" items
• Verify test-babel-ast.sh passes with the expected fixture count
• Update the plan doc's status section