fix(ci): guard the pantry-env evals in package.json too, which #107 missed

#107 removed eval "$(pantry env …)" from 16 sites across five workflows and said so. It missed eight more in package.json, and integration on #108 found them.

The "Run root verification" step runs bun run verify → build:core → eval "$(pantry env …)" → the workspace setup:

✗ Patch failed for ts-maps
error: Cannot find package 'typescript' from …/packages/typescript/scripts

Same clobbered node_modules, one door further along. The failing step moved from "Build TypeScript SDK" to "Run root verification"; the cause did not change.

Guarded, not removed

These are not the workflow's sites and they are not redundant the same way. In CI the pantry action puts zig on PATH, so command -v zig short-circuits and no workspace setup runs. On a developer's machine zig is usually not on PATH, and this eval is how these scripts have always made it available — that path is unchanged.

Verified both directions

• zig on PATH → guard skips the eval, bun run fmt:check exits 0.
• zig absent → eval runs exactly as before.

Unblocks #108, whose integration failed on this.