RV-F7: confirmed header mappings silently ignored (API model has no headerMapping field) #186

What happened

External repo review at commit c7bebd1: the frontend sends headerMapping; the API request model in api/routers/csv_routes.py L38–45 has no such field. Pydantic silently discards it. Confirmed header renames leave the imported column name unchanged.

Code paths:

• csv-table-hub-main/src/lib/csv.functions.ts L151–171 (frontend sends it)
• api/routers/csv_routes.py L38–45 (API ignores it)

Why this matters

The advertised "confirm header mapping" control does nothing. User expects renamed columns in the imported table; gets the original CSV headers. No error, no indication the mapping was dropped.

Two acceptable resolutions:

• Implement: add headerMapping to the API request model, validate it, apply it during the load.
• Remove: drop the UI control entirely so users don't see a broken feature.

Either is better than the current state.

Proposed

Decision needed on the issue:

• (a) Implement a validated mapping contract (API model + loader passes mapping into dynamic/T&E load paths).
• (b) Remove the ineffective UI control.

Claude recommends (a) for dynamic mode (where user-friendly column renames are useful) and (b) for T&E mode (where columns must match the fixed schema exactly, so renaming is moot).

Tests must assert the resulting database column names, not just the frontend request object.

Done when

• Decision (a) or (b) taken.
• If (a): reproduction test maps foo → bar and asserts the DB column is bar.
• If (b): UI control removed and vitest coverage of the removal.

Reference

Tracker row G50. Repo review finding RV-F7. Related: #154 frontend decision affects (b) (the UI control is in Lovable code).