feat(content): about.html — intent, provenance, honest limits; static-build copy

English-first page mirroring credits.html (for-everyone / tech arc
underwater→drones→space / built-with-LLMs / honest-it's-imperfect). Header
link + about.link i18n key; about.html + flash.js added to PUBLIC_ASSETS.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tools/build_static.py

@@ -36,7 +36,7 @@ from simulator.app import MEDIA_DIR, create_app
 STATIC = Path(__file__).resolve().parent.parent / "simulator" / "static"
 # Frontend files that ship; everything else in static/ (author*, review*) is dev-only.
 PUBLIC_ASSETS = ["index.html", "app.js", "scrub.js", "i18n.js", "alteration.js", "style.css",
-                 "credits.html", "credits.js"]
+                 "credits.html", "credits.js", "about.html", "flash.js"]
 
 
 def _bake_api(app_dir: Path) -> dict: