chore: consolidate pnpm config to .npmrc

Remove pnpm-workspace.yaml and consolidate all pnpm configuration in .npmrc.
This is a single-package repo, not a workspace, so workspace file is unnecessary.

Changes:
- Delete pnpm-workspace.yaml
- Move trust-policy config to .npmrc
- Remove unnecessary comments from .npmrc
- Keep all settings: ignore-scripts, workspace suppressions, trust policy

All configuration now in one place for single-package repo.

Author: jdalton

.npmrc

@@ -1,7 +1,7 @@
-# Suppress pnpm build script warnings.
 ignore-scripts=true
-
-# Suppress pnpm workspace warnings
 link-workspace-packages=false
 loglevel=error
-prefer-workspace-packages=false
+prefer-workspace-packages=false
+trust-policy=no-downgrade
+trust-policy-exclude[]=@yarnpkg/core@4.5.0
+trust-policy-exclude[]=@yarnpkg/libzip@3.2.2