feat: Caelis Engine v4.0 — complete architectural rewrite

- Pure astronomical schema v3.1 (zero interpretive concepts in core)
- A.T.A.C.I.R. plugin system with Plugin Contract R1-R5
- Validation suite 28/28 passing across 5 reference epochs
- Full documentation suite
- AGPL-3.0 dual license model
- AtacirClient.js open source API client

Caelis Engine 3.0 — VSOP87B Mercurio, Armilar Mode 3D, Rise/Set Meeus…

… Cap.15

chore: inscribir autoria Cristian Valeria Bravo / Hermetica Labs