scripts: check-cross-plugin-source-drift.sh breaks on paths containing whitespace

[kyle-sexton]

Context

Found by the repo-wide /code-tidying:batch-simplify sweep (62 groups / 986 files, branch claude/repo-code-tidying-batch-twhddw). The sweep's doctrine files latent defects instead of fixing them mid-sweep, because the fix changes observable behavior; this issue is that filing.

scripts/check-cross-plugin-source-drift.sh:120,68-76 — unquoted command-substitution iteration and word-splitting break on whitespace paths. Latent: no current registered path contains whitespace.

Proposed work

• Quote the expansions / switch the iteration to a while-read or array form.

Acceptance criteria

• A registry entry with a space in its path is processed correctly (fixture test).

References

• scripts/check-cross-plugin-source-drift.sh:68-76
• scripts/check-cross-plugin-source-drift.sh:120

Filed by the /code-tidying:batch-simplify closeout (Phase 8).

[kyle-sexton]

This was generated by AI during work-loop.

Already fixed on main by 3eaae230 (PR #3392, which closed #3376). #3428 is the same word-splitting defect, re-filed later against the pre-fix line numbers.

load_cluster now uses newline-delimited mapfile, and discover mode sorts through a quoted array. The acceptance fixture (hooks/shared file.sh) is in scripts/check-cross-plugin-source-drift.test.sh (PASS=12).

Closing as a duplicate of #3376.