refactor: tighten local lint and windows codegen guard

[qartik]

Summary

Split out the independent cleanup work from #48.

Included

• tighten local cargo-clippy pre-commit arguments to use --locked, -D warnings, clippy::pedantic, and clippy::nursery
• inline the Windows optimized-codegen guard in src/opt.rs instead of keeping a platform-specific stub helper
• apply the minimal src/lib.rs visibility and test-call cleanups needed for the stricter clippy configuration to pass on top of main

Notes

• this is intended to keep feat: support dynamic allocation and arrays #48 focused on dynamic allocation and arrays
• behavior is unchanged aside from the existing Windows optimized-codegen error path still being enforced through the inlined guard

[Copilot]

Pull request overview

This PR tightens local linting enforcement while keeping behavior unchanged, and simplifies Windows-specific codegen guarding by inlining it directly at the call site.

Changes:

• Tighten the cargo clippy pre-commit hook to use --locked and treat warnings as errors (-D warnings) alongside clippy::pedantic/clippy::nursery.
• Inline the Windows optimized-codegen guard directly in optimize() and remove the platform-stub helper.
• Make small formatting/visibility/test-call adjustments to satisfy stricter lint settings.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/opt.rs	Removes the platform-stub helper and inlines the Windows guard in optimize().
src/lib.rs	Adjusts visibility of module-flag helpers and cleans up a few format! call sites / test mapping.
.pre-commit-config.yaml	Makes clippy stricter by adding --locked and -D warnings to pre-commit args.

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