fix(assistant): advance Life Pulse periodic growth anchor

[cursor]

Summary

• Desktop Life Pulse never advanced last_periodic_growth_unix, so inspect_growth_due treated every heartbeat as first-tick and the advertised periodic evolution arm never fired.
• After a successful skilllite evolution status --json inspect, seed a missing anchor to now and refresh it when arm_periodic is true (including skipped no-proposal ticks), matching in-process growth_due.

Task Linkage

• Task ID: TASK-2026-071
• Task folder: tasks/TASK-2026-071-life-pulse-periodic-anchor/

Injected Specs

• spec/architecture-boundaries.md (if architecture/layering changed)
• spec/security-nonnegotiables.md (if sandbox/security changed)
• spec/testing-policy.md (required for any code change)
• spec/docs-sync.md (if behavior/docs/env/commands changed)

Also injected: spec/verification-integrity.md, spec/task-artifact-language.md, spec/rust-conventions.md.

Validation Evidence

• Commands executed:
  • python3 scripts/validate_tasks.py
  • rustfmt --check --edition 2021 crates/skilllite-assistant/src-tauri/src/skilllite_bridge/integrations/evolution_ui/growth.rs
  • cargo fmt --check
  • cargo clippy --all-targets -- -D warnings
  • cargo test
  • cargo test --manifest-path crates/skilllite-assistant/src-tauri/Cargo.toml next_periodic_anchor
  • cargo test --manifest-path crates/skilllite-assistant/src-tauri/Cargo.toml should_spawn_growth
• Key results:
  • Task validation: Task validation passed (71 task directories checked).
  • Workspace clippy/tests: exit 0
  • Targeted assistant tests: 6 passed (next_periodic_anchor_*, should_spawn_growth_*)

Regression Scope

• Areas likely affected:
  • Desktop Life Pulse periodic growth spawn cadence
• Explicit non-goals:
  • Rhythm schedule tick --workspace (fix(assistant): pass workspace to life pulse rhythm #115/Fix Life Pulse rhythm workspace scoping #116)
  • Evolution reset/repair workspace roots
  • ChatSession workspace alignment

Docs Sync (EN/ZH)

• Not needed
• Updated EN + ZH docs
• Files:
  • Code now matches already-documented A9 periodic interval in docs/en/ENV_REFERENCE.md / docs/zh/ENV_REFERENCE.md.

Review Checklist

• Acceptance criteria in tasks/TASK-2026-071-life-pulse-periodic-anchor/TASK.md satisfied (or explicitly deferred)
• tasks/TASK-2026-071-life-pulse-periodic-anchor/STATUS.md updated with latest progress
• tasks/TASK-2026-071-life-pulse-periodic-anchor/REVIEW.md includes merge readiness decision
• tasks/board.md status is up to date

Bug / impact

Enable Life Pulse with high signal/sweep thresholds so only the periodic arm can fire, then wait past SKILLLITE_EVOLUTION_INTERVAL_SECS. Expected: spawn skilllite evolution run. Actual: no periodic spawn. Chat/agent-rpc still worked because it uses mutating growth_due.

Root cause

L2 evolution_growth_due read the mutex and passed it to inspect-only CLI status, but never wrote the mutex. inspect_growth_due uses anchor_eff = last.unwrap_or(now), so a persistent None keeps arm_periodic false.

Fix

After inspect, persist None -> now and refresh on arm_periodic. Spawn gating is unchanged.