Nothing prunes it, atm. Currently I'm not sure if it's valuable that it does? 97KB is ~25k tokens. `grepathy context <file>` filters by the decision's Touches: list - a typical file pulls 3KB, not 97. But, I'm open to hearing a case on pruning!

For comparison the whole git log body on that branch is 3KB; the pack holds 33x the reasoning.