fix(workbook): preserve stable column IDs across display aliases

[rudycelekli]

Summary

Preserve workbook stable column IDs when another column's display name collides with them.

• Read input fields from an immutable copy of the stored row while keeping the original alias assignment order and failed computed-value invalidation.
• Build condition aliases separately, so a display name cannot overwrite a stable ID.
• Add ten cases through the real public HTTP routes and persisted SQLite rows: eight stable-ID cases plus two controls preserving intentional ambiguous-name rejection.

Native verification

The existing four CI jobs are unchanged.

• Original BEFORE: three assertion failures reproduced the two affected paths; five controls passed. SQLite: 3 failed, 2097 passed, 134 skipped, 3 deselected.
• Corrected ten-case BEFORE: the same three failures; both ambiguous-reference rejection controls passed. SQLite: 3 failed, 2099 passed, 134 skipped, 3 deselected.
• Current AFTER at 4644882: all four jobs succeeded. SQLite: 2102 passed, 134 skipped, 3 deselected; PostgreSQL: 18 passed; frontend: 63 passed plus lint/build; browser regressions: 3 passed. All ten added cases and the 2092 original SQLite cases pass.

The original eight assertions were preserved throughout. An earlier supplemental fixture incorrectly expected successful ambiguous-name resolution; its two failures were rejected as fixture errors and add no defect evidence. The final two controls freeze the actual typed rejection contract. The earlier two-pass source was superseded by the immutable input snapshot; its passing run is not used as current-head qualification.

Scope and review

This changes only two workbook source files and their existing HTTP test owner. PR #65 changes the numeric comparator in a separate hunk; that comparator is byte-identical here, and no unmerged source from #65 is included. No workflow, provider call, tenancy or application execution behavior is added.

Prepared with AI assistance; source and native evidence were independently reviewed. All three candidate commits have verified signatures and DCO signoffs.

Upstream CI is pending for this newly submitted pull request; the results above are from the exact current head in the author fork.