Mermaid purge — 4-phase plan (issue #21)

Cycle 1 · P1 — build

Cycle 2 · P2 — migrate

Cycle 2 · P3+P4 — delete + guard

V1 primitives (fg-axis-date, fg-lifeline, fg-er-*)

V2 rename + ship 3 native templates

V3 sequence + state + dep-graph

5 SKILL.md migrations

gen-deps.py rewrite (elbow routing)

render-md*.py hard-error fences

Delete Mermaid sources + README cleanup

Blocking grep guard + CI mirror

Close #19 (superseded)

Apr 15

Apr 22

Apr 29

May 06

May 13

amber = P1 build · cyan = P2 migrate · purple = P3 delete · red = close issue