remove remaining todo

TODO.md

@@ -5,34 +5,6 @@ ordered roughly by priority within each section. Priority labels
 (`HIGH` / `MEDIUM` / `LOW`) mark items that deserve explicit
 ranking; unlabeled items are "someday, if the mood strikes."
 
-## Investigate: detailed 401(k) contributions data source
-
-Found a more detailed contributions screen on at least one
-employer-sponsored 401(k) provider portal - distinct from the
-standard positions/holdings view we already pull from. Worth
-investigating whether this unlocks better attribution than what
-we get from the positions CSV alone, and whether other 401(k)
-providers expose similar screens.
-
-Open questions to answer when picking this up:
-
-- Which screen specifically (path / URL within the portal)? Is there
-  an export option, or is it view-only / scrape territory?
-- What fields does it expose (employee pre-tax, employer match,
-  after-tax / mega-backdoor, by-pay-period dates, per-fund
-  allocations)?
-- Refresh cadence - per-paycheck, daily, on-demand?
-- Can it be auto-discovered like the existing audit CSVs, or
-  is it manual-entry territory?
-
-If the export is structured and recurring, this could feed a
-401(k)-specific contributions classifier that bypasses the lot-diff
-heuristic for that account, similar to how `cash_is_contribution`
-opts ESPP/HSA accounts into cash-based attribution.
-
-Related: ESPP-style accrual blind spot in the "Audit: manual-check
-accounts mechanism" section above.
-
 ## Infra / performance
 
 - **HTTP connection pooling.** Parallel server sync in `loadAllPrices`