Add AI-relevant source domains to cultural-references.md

[glacierphonk]

Summary

Adds a Source Domains for AI Products section to cultural-references.md, grouping four reference families specifically relevant to naming AI products:

1. Sci-fi AI characters — with explicit saturation flags (oversaturated · moderately used · underexplored), so the skill suggests Wintermute/Jane/Mike/Multivac before HAL/Skynet
2. Computing pioneers — Shannon, Babbage, Hopper, Dijkstra, Knuth, Hamming, Backus, Boole, Lovelace, Wiener (with note that Claude/Ada/Turing are already in use)
3. Mythology of knowledge/wisdom — Athena, Thoth, Saraswati, Odin (sacrifice-for-knowledge metaphor), Prometheus (collision risk flagged), Ganesha
4. Cognitive-science concepts — gestalt, schema, heuristic, qualia, metacognition, salience, valence, affordance

Each subsection includes saturation notes, sound character, and caveats (already-occupied names, audience requirements, living-person restrictions).

Scope

• One file modified: cultural-references.md (+55/-1)
• Section placed before Multi-Level Names so all source-domain content stays adjacent (next to the existing Source Domains Beyond Greek Mythology and Celtic mythology sections)
• markdownlint-cli2 '**/*.md' passes (0 errors)

Closes #178

Test plan

• markdownlint-cli2 '**/*.md' passes
• Verify section renders cleanly on GitHub
• Sanity-check saturation flags (Wintermute, Jane, Mike still underused; Cortana/Prometheus correctly flagged as occupied)