docs: product-facing README; archive CST theory notes (0.9.34)

Rewrite the homepage for day-to-day use, move paper/eval drafts under
docs/archive, and add a docs index so theory no longer leads the project.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/replay_starvation.sh

@@ -5,4 +5,4 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd)"
 cd "$ROOT"
 make check
 echo
-echo "See docs/theory_tool_cst.md for the claim under test."
+echo "Historical note: docs/archive/theory_tool_cst.md (not product docs)."