docs: rename self-references from "LLM Wiki" to "memex"

Replace project self-references throughout README, SETUP, and the example
CLAUDE.md files. External artifact titles are preserved as-is since they
refer to the actual title of the Claude design artifact.

Also add a "Why 'memex'?" aside to the README that roots the project in
Vannevar Bush's 1945 "As We May Think" essay, where the term originates.
The compounding knowledge wiki is the LLM-era realization of Bush's
memex concept: the "associative trails" he imagined are the related:
frontmatter fields and wikilinks the agent maintains.

Kept lowercase where referring to the generic pattern (e.g. "an LLM wiki
persists its mistakes") since that refers to the class of system, not
this specific project.

README.md

@@ -1,8 +1,8 @@
-# LLM Wiki — Compounding Knowledge for AI Agents
+# memex — Compounding Knowledge for AI Agents
 
 A persistent, LLM-maintained knowledge base that sits between you and the
 sources it was compiled from. Unlike RAG — which re-discovers the same
-answers on every query — the wiki **gets richer over time**. Facts get
+answers on every query — memex **gets richer over time**. Facts get
 cross-referenced, contradictions get flagged, stale advice ages out and
 gets archived, and new knowledge discovered during a session gets written
 back so it's there next time.
@@ -11,7 +11,22 @@ The agent reads the wiki at the start of every session and updates it as
 new things are learned. The wiki is the long-term memory; the session is
 the working memory.
 
-> **Inspiration**: this combines the ideas from
+> **Why "memex"?** In 1945, Vannevar Bush wrote
+> [*As We May Think*](https://www.theatlantic.com/magazine/archive/1945/07/as-we-may-think/303881/)
+> describing a hypothetical machine called the **memex** (a portmanteau
+> of "memory" and "index") that would store and cross-reference a
+> person's entire library of books, records, and communications, with
+> "associative trails" linking related ideas. He imagined someone using
+> it would build up a personal knowledge web over a lifetime, and that
+> the trails themselves — the network of learned associations — were
+> more valuable than any individual document.
+>
+> Eighty years later, LLMs make the memex finally buildable. The
+> "associative trails" Bush imagined are the `related:` frontmatter
+> fields and wikilinks the agent maintains. This repo is one attempt
+> at that.
+
+> **Inspiration**: memex combines
 > [Andrej Karpathy's persistent-wiki gist](https://gist.github.com/karpathy/442a6bf555914893e9891c11519de94f)
 > and [milla-jovovich/mempalace](https://github.com/milla-jovovich/mempalace),
 > and adds an automation layer on top so the wiki maintains itself.