chore: sync vault to ~/cosmic-brain (Obsidian-registered path)

wiki/concepts/Hot Cache.md

@@ -0,0 +1,95 @@
+---
+type: concept
+title: "Hot Cache"
+complexity: basic
+domain: knowledge-management
+aliases:
+  - "hot.md"
+  - "Session Cache"
+  - "Context Cache"
+created: 2026-04-07
+updated: 2026-04-07
+tags:
+  - concept
+  - knowledge-management
+  - context
+status: mature
+related:
+  - "[[LLM Wiki Pattern]]"
+  - "[[Compounding Knowledge]]"
+  - "[[index]]"
+  - "[[hot]]"
+sources:
+  - "[[wiki/sources/Nate Herk LLM Wiki Transcript]]"
+---
+
+# Hot Cache
+
+A ~500-word summary of the most recent context in the wiki vault. Stored in `wiki/hot.md`. Updated at the end of every session and after every significant ingest or query.
+
+The hot cache exists to answer one question: "where did we leave off?" A new session reads `hot.md` first. If the answer is there, it skips crawling the rest of the wiki.
+
+---
+
+## What It Stores
+
+- What was most recently ingested or discussed
+- Key recent facts and takeaways
+- Pages recently created or updated
+- Active threads and open questions
+- What the user is currently focused on
+
+---
+
+## Format
+
+```markdown
+---
+type: meta
+title: "Hot Cache"
+updated: YYYY-MM-DDTHH:MM:SS
+---
+
+# Recent Context
+
+## Last Updated
+YYYY-MM-DD — [what happened]
+
+## Key Recent Facts
+- [Most important recent takeaway]
+- [Second]
+
+## Recent Changes
+- Created: [[New Page 1]]
+- Updated: [[Existing Page]] (added section on X)
+- Flagged: Contradiction between [[Page A]] and [[Page B]]
+
+## Active Threads
+- User is researching [topic]
+- Open question: [thing being investigated]
+```
+
+---
+
+## Rules
+
+- Keep it under 500 words. It is a cache, not a journal.
+- Overwrite it completely each time. Not append-only.
+- One file. Not split by date.
+- Updated after every ingest, significant query, and at the end of each session.
+
+---
+
+## Why It Matters
+
+Without the hot cache, every session starts cold: read the index (1000 tokens), read several domain sub-indexes, read several individual pages. With the hot cache, the first 500 tokens often have everything needed.
+
+Nate Herk reported that adding `hot.md` to his executive assistant vault reduced the token cost of session startup significantly compared to crawling multiple wiki pages.
+
+The hot cache is especially valuable in cross-project setups: another Claude Code project can point at this vault and read `hot.md` first to get recent context at minimal token cost.
+
+---
+
+## Connections
+
+The hot cache is part of the [[LLM Wiki Pattern]] token discipline strategy. See [[index]] for how the broader navigation works.