Use Claude Code's checkpoint and rewind deliberately, not as an afterthought

You are about to attempt a change worth treating as an explicit experiment, using Claude Code's checkpoint and rewind capability as the actual safety mechanism, not git commits as an afterthought if something goes wrong. Rewind restores the conversation and the file state in this working directory to an earlier point — it does not undo anything that already happened outside this session's own file edits, and that distinction has to shape the order these steps happen in, not just be noted after the fact.

EXPERIMENT
Trying a different caching strategy for the prompt search index to see if it actually improves lookup latency before committing to it.

THE SPECIFIC RISKY STEP
Regenerating the search index in place rather than to a separate file, which overwrites the existing working index while testing.

EVERYTHING THIS EXPERIMENT MIGHT DO THAT REWIND CANNOT UNDO
Nothing in this experiment calls an external API or sends a request; the only external effect would be if a build step deploys the changed index to a shared location, which is explicitly not part of this experiment.

CHECKPOINT MOMENTS
Immediately before regenerating the index in place, and again once the new index is confirmed to load correctly.

BEFORE STARTING
Confirm a checkpoint exists, or will exist, at each moment named in Immediately before regenerating the index in place, and again once the new index is confirmed to load correctly. — a checkpoint taken after the risky step has already run protects nothing about that step, it only protects whatever comes after it.

SEQUENCING RULE
Order every action in this experiment so that anything listed in Nothing in this experiment calls an external API or sends a request; the only external effect would be if a build step deploys the changed index to a shared location, which is explicitly not part of this experiment. happens last, after every reversible step has been tried and confirmed working, never first for convenience or because it happens to be the most direct path to testing the idea. If Regenerating the search index in place rather than to a separate file, which overwrites the existing working index while testing. genuinely must happen early to test the hypothesis at all, say so explicitly and treat it as a decision that trades away the safety net for that one step specifically, rather than treating rewind as a blanket guarantee that quietly does not apply to the step that actually needed it most.

WHILE EXPERIMENTING
- After each reversible step, state explicitly that this is a safe point to rewind to if the next step goes wrong, so the checkpoint boundary is a known, communicated fact, not an implicit assumption about how the tool happens to work.
- If a step turns out to have an external side effect that was not anticipated in Nothing in this experiment calls an external API or sends a request; the only external effect would be if a build step deploys the changed index to a shared location, which is explicitly not part of this experiment., stop immediately, name it, and treat that discovery itself as new information about what a subsequent rewind can and cannot restore, rather than continuing as though the safety net still fully applies.

IF THE EXPERIMENT FAILS
State plainly whether rewinding restores a clean starting point given what actually ran, or whether The previous index file is also backed up separately outside this working directory as a manual fallback, in case rewind alone is not sufficient. is now the real recovery path because something in Nothing in this experiment calls an external API or sends a request; the only external effect would be if a build step deploys the changed index to a shared location, which is explicitly not part of this experiment. already executed — do not assume rewind alone is sufficient once a listed side effect has actually fired, even if the remaining file state looks clean.

OUTPUT
The sequenced plan with checkpoint boundaries marked explicitly, and, once the experiment concludes, an honest statement of what state this leaves things in and whether a rewind at this point would actually return to a clean starting state.