Extract stripDiffSearchParams helper to deduplicate diff param stripping logic

Consolidate the repeated pattern of destructuring and removing diff/diffTurnId/diffFilePath
search params into a single stripDiffSearchParams() function in diffRouteSearch.ts.
Replaces 5 identical destructuring blocks across 3 files with calls to the shared helper.

Applied via @cursor push command
842e327583Cursor Agent committed on 2/19/2026, 11:36:12 PMparent891eb02
4 files changedLine totals unavailable