Implement writ adopt --from-receipt #70

Summary

Implement the --from-receipt flag for writ adopt that reads a lore receipt and adopts the packages-manifest.yaml and config files into the environment repository.

Current State

The function runAdoptFromReceipt() is a stub that returns an error (previously returned success, fixed in #65).

Location: internal/writ/commands.go:1202-1211

Requirements

1. Read a lore receipt from the specified path (or ~/.local/state/devlore/receipts/lore-latest.yaml if not specified)
2. Parse the receipt to extract:
   • packages-manifest.yaml that was deployed
   • Any config files that were templated
3. Adopt these files into the specified layer/project using the existing adopt logic

Documentation References

• writ adopt CLI docs - Documents the --from-receipt flag
• Receipts User Guide - Receipt format and location
• Receipt Integrity Architecture - Receipt structure (v4 format)

Acceptance Criteria

• writ adopt --from-receipt reads the most recent lore receipt
• writ adopt --from-receipt <path> reads the specified receipt
• Adopted files are placed in <layer>/<scope>/<project>/
• Symlinks are created back to original locations
• Tests verify the feature works correctly

Epic: #447 · Feature: #463