fix: remove Nate Herk source page + all references

Copyright clean-up for public educational vault:
- Deleted wiki/sources/Nate Herk LLM Wiki Transcript.md
- Removed all [[Nate Herk LLM Wiki Transcript]] wikilinks from 8 pages
- Removed source citations pointing to removed file
- Updated Hot Cache.md: removed attribution to specific person
- Updated Andrej Karpathy.md: first_mentioned now points to concept page
- Updated Wiki Map.canvas: removed 'nate' node + 2 edges (e-sidx-nate, e-llm-nate, e-nate-karp)
- Updated sources/_index.md: empty transcripts section
- Updated index.md, hot.md, log.md, overview.md: no Nate Herk entries

Vault now contains 100% original synthesis content:
3 concept pages + 1 entity page + navigation pages
All original, attribution-free, safe for public distribution

.obsidian/graph.json

@@ -53,6 +53,6 @@
   "repelStrength": 20,
   "linkStrength": 1,
   "linkDistance": 385,
-  "scale": 0.42105482394501453,
+  "scale": 0.48198745386564384,
   "close": false
 }

.obsidian/workspace.json

@@ -189,6 +189,11 @@
   },
   "active": "c0d470cf50ffdf79",
   "lastOpenFiles": [
+    "wiki/Wiki Map.canvas.tmp.224546.1775555483542",
+    "wiki/entities/Andrej Karpathy.md.tmp.224546.1775555435117",
+    "wiki/concepts/Hot Cache.md.tmp.224546.1775555433665",
+    "README.md.tmp.224546.1775555144441",
+    "cover.gif",
     "bin/setup-vault.sh.tmp.224546.1775554739080",
     "projects/visual-vault/design-ideas.canvas",
     "projects/visual-vault/design-ideas.canvas.tmp.224546.1775554654804",
@@ -203,14 +208,9 @@
     "_attachments/images/skool-hub/sq-01.png",
     "_attachments/images/skool-hub/pro10-var-20.png",
     "_attachments/images/skool-hub/pro10-var-10.png",
-    "_attachments/images/skool-hub/pro10-var-01.png",
     "_attachments/images/skool-hub",
     "_attachments/images",
     "_attachments",
-    "README.md.tmp.224546.1775554365748",
-    "bin/setup-vault.sh",
-    "bin/setup-vault.sh.tmp.224546.1775554319795",
-    "bin",
     "wiki/entities/_index.md",
     "wiki/meta/dashboard.md",
     "wiki/sources/_index.md",