feat(memory): DPLAN-0207 P3-P5 — unify spawn templates + /memo,/prep entry rule; manager.py E402 fix
P3: birthright+builder local/observations templates to unified schema (key_learnings dict->list, session_number->number, pattern/source->note, number+date+tags, schema 3.0.0)
P4: edit_gate verified list-aware via changed_entries dispatch — no code change needed
P5: /memo + /prep + memo SKILL carry the unified entry rule (stamp number+date, newest-on-top, prepend, no hand-trim)
Fix: manager.py E402 (import below logger) leftover from FPLAN-0273 hotfix — was blocking the .py diagnostics edit-gate
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
