[Feature Request] Add --reapply-ignore flag to --resume for filtering cached content against updated .claudeignore

Question

**Bug Description**
Feature request: Add a --reapply-ignore flag to --resume that re-filters the session history against the current .claudeignore, stripping cached file contents from now-ignored paths.

Problem: resuming sessions after adding .claudeignore still loads old cached content, causing UI render freezes on large repos. Observed in a session where diagnosis identified a 601KB session with 6.7GB of previously-scanned directories, causing a render loop even after .claudeignore was added.