fix(atlas): address PR #106 review — 3 execution issues

1. GJ 111: spectral_class F5V → F5/F6V to match wiki (subgiant)
2. GJ 3943: spectral_class k-m → K5V+M3V (valid MK notation for binary)
3. GJ 903: write wiki prose — was empty stub with only body tables

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/atlas/proposals/GJ111.json

@@ -2,7 +2,7 @@
   "system_id": "GJ 111",
   "proper_name": "Helderoog",
   "star_type": "F",
-  "spectral_class": "F5V",
+  "spectral_class": "F5/F6V",
   "wiki_data": {
     "habitable_count": 1,
     "inhabited_count": 1,

docs/atlas/proposals/GJ3943.json

@@ -1,8 +1,8 @@
 {
   "system_id": "GJ 3943",
   "proper_name": "GJ 3943",
-  "star_type": "unusual",
-  "spectral_class": "k-m",
+  "star_type": "K+M",
+  "spectral_class": "K5V+M3V",
   "wiki_data": {
     "habitable_count": 1,
     "inhabited_count": 0,