docs: README hook, discoverability, Pages site, game-behaviour reference

- README: lead with what it is + the AI-agent-collaboration research
  framing + current status in the first paragraph; rename H1 to
  "GoldenEye 007 PC Port"; add a live CI badge.
- New "How this differs from the other GoldenEye PC projects" section:
  this is a source port of the N64 original; the Recomp projects
  binary-translate the Xbox 360 XBLA remaster (different game, no shared
  code).
- CITATION.cff for GitHub's "Cite this repository" widget / Zenodo.
- GitHub Pages site off /docs (_config.yml + index.md landing page).
- agentic-development.md: searchable title + abstract.
- .github/social-preview.{png,html,md}: repo social-preview card styled
  after the GE mission-briefing screen, kept editable (CSS source + a
  regen/how-to doc beside the PNG).
- docs/dev/game-behavior-reference.md: distilled the raw GameFAQs
  walkthrough dump down to the behaviour-defining parts (combat/AI model,
  difficulty scaling, per-level objective sets, timers, weapon data,
  original-game quirks). Credits: Brett "Nemesis" Franklin, marshmallow.

Claude-Session: https://claude.ai/code/session_01GULf6knbsqfsnW39tMr9WT

docs/dev/agentic-development.md

@@ -1,10 +1,12 @@
-# Agentic development: a two-agent experiment
+# Agentic development: two AI coding agents porting GoldenEye 007
 
-*A GoldenEye 007 N64→desktop port, taken from "builds a ROM" to "playable front
-end" in about two weeks — driven mostly by two coding agents, a local
-open-weight model and a hosted frontier model, handing work back and forth
-through shared written notes under one person's direction. This is the goal,
-the method, the timeline, and an honest read on what did and didn't work.*
+*A case study in AI-agent collaboration on a large, low-level codebase. A
+GoldenEye 007 Nintendo 64 → desktop port, taken from "builds a ROM" to
+"playable front end" in about two weeks — driven mostly by two coding agents (a
+local open-weight model, Qwen 3, on a single RTX 5090, and a hosted frontier
+model, Claude / Claude Code), handing work back and forth through shared
+written notes under one person's part-time direction. This is the goal, the
+method, the timeline, and an honest read on what did and didn't work.*
 
 ## Contents