Edges Linear restructure to Vision & Plan (Notion doc)

Rebuilt Linear project to match Edges — Design Operating System Vision & Plan. Renamed M0/M0.5/M0.75/M1/M2/M3/M4/M5/M6/M7 → Phase 0/0.5/1/2/4/5/7. Created new Phase 1 (Shell+Nav), Phase 3 (Agent Corpus), Phase 6 (Create/Workbench). Canceled 13 stale M4 breakdown issues (ALL-795..807). Created ALL-812 (PR 0 — Site direction + shell foundations) and ALL-813 (PR 1 — Principles + agent-readable basics) under Phase 1. Fixed milestone sort order. Project description + overview updated.