fix: scope evolution disable/explain and migrate memory roots

[cursor]

Summary

• Fix evolution disable / explain mutating/reading global ~/.skilllite/chat instead of the selected workspace chat/ root by adding --workspace/-w and routing through chat_root_for_workspace.
• Fix claw migrate / migrate openclaw writing OpenClaw memory into global chat memory despite --workspace; memory now lands under <workspace>/chat/memory (plan display, apply, and reindex).
• Harden skilllite_fs::atomic_write staging so same-stem siblings (examples.json / examples.md) and .tmp destinations no longer share one temp path (follow-up to artifact staging fix in fix: prevent artifact temp collisions and proposal ID clashes #133).

Bug and Impact

• evolution disable from a project without SKILLLITE_WORKSPACE could not find project rules and instead disabled rules in ~/.skilllite/chat/prompts/rules.json, leaving the intended project rules active.
• claw migrate -w <project> copied MEMORY.md / daily notes into ~/.skilllite/chat/memory, splitting persona/skills (project) from memory (global) and risking cross-project data leakage.
• Shared with_extension("tmp") staging can cross-corrupt concurrent writes to same-stem different extensions.

Task Linkage

• Task ID: TASK-2026-082
• Task folder: tasks/TASK-2026-082-path-root-scoping-atomic-write/

Injected Specs

• spec/verification-integrity.md
• spec/task-artifact-language.md
• spec/architecture-boundaries.md
• spec/security-nonnegotiables.md
• spec/rust-conventions.md
• spec/testing-policy.md
• spec/docs-sync.md

Validation Evidence

• Commands executed:
  • cargo test -p skilllite-fs --lib
  • cargo test -p skilllite-commands --lib plan_marks_soul_and_memory
  • cargo test -p skilllite --test cli_evolution_workspace
  • migrate dry-run PoC under isolated HOME
  • cargo clippy -p skilllite-fs -p skilllite-commands -p skilllite --all-targets -- -D warnings -A clippy::question_mark -A clippy::useless_borrows_in_formatting
  • cargo fmt --check
  • python3 scripts/validate_tasks.py
• Key results:
  • skilllite-fs: 9 passed (includes atomic_write stem + .tmp destination)
  • cli_evolution_workspace: 2 passed (includes disable workspace isolation)
  • migrate PoC: Memory dir under <project>/chat/memory, not ~/.skilllite/chat/memory
  • task validation: 71 task directories checked passed

Regression Scope

• Areas likely affected:
  • Evolution disable/explain CLI parsing and chat-root resolution
  • OpenClaw migrate memory plan/apply/reindex destination
  • All skilllite_fs::atomic_write callers
• Explicit non-goals / already covered by other open PRs:
  • fix(evolution): constrain pending skill path operations #89, fix(artifact): reject Windows path escapes in store keys #123–fix: prevent artifact temp collisions and proposal ID clashes #133 path escapes
  • reset/repair workspace scoping (Fix evolution reset and repair workspace roots #113/fix(evolution): scope destructive reset to requested workspace #120)

Docs Sync (EN/ZH)

• Updated EN + ZH docs
• Files:
  • README.md
  • docs/zh/README.md
  • docs/en/ASSISTANT-SPLIT-ARCHITECTURE.md
  • docs/zh/ASSISTANT-SPLIT-ARCHITECTURE.md

Review Checklist

• Acceptance criteria in tasks/TASK-2026-082-path-root-scoping-atomic-write/TASK.md satisfied
• STATUS.md updated with validation evidence
• REVIEW.md includes merge readiness decision
• tasks/board.md status is up to date