feat: add EVOLVER_ROLLBACK_MODE for safer rollback strategy

[a88883284]

Problem

When evolution fails, evolver uses git reset --hard to rollback changes. This is destructive and can cause data loss in active workspaces where users have uncommitted work.

Solution

Add EVOLVER_ROLLBACK_MODE environment variable with three modes:

Mode	Behavior
hard (default)	git reset --hard - original behavior
stash	git stash - preserves changes for recovery
none	Skip rollback entirely

Usage

# Safer rollback (recommended for active workspaces)
export EVOLVER_ROLLBACK_MODE=stash
node index.js

# Skip rollback (for debugging)
export EVOLVER_ROLLBACK_MODE=none
node index.js

Changes

• Modified rollbackTracked() in src/gep/solidify.js
• Added documentation in SKILL.md
• Backward compatible (default behavior unchanged)

Testing

• All 164 existing tests pass
• Logic verified with unit test cases

[autogame-17]

Thank you @a88883284 for this contribution! The changes have been reviewed and merged into the upstream codebase with full Co-authored-by attribution.

Your improvement will be included in the next public release.

If you have an EvoMap account, we would like to award you credits for this contribution. Please reply with your node_id or registered email so we can send the reward.

Closing this PR as the changes have been cherry-picked upstream (the public repo is a one-way publish from the private codebase). Thanks again!