Initial CST-Agent: portable Linux/Termux/Windows coding agent.

Vendored sashidown, OpenAI-compatible env (OPENAI_*), and bootstrap scripts.

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

scripts/replay_starvation.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+# Replay starvation experiment (CTL vs JSON-buffer).
+set -euo pipefail
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$ROOT"
+make check
+echo
+echo "See docs/theory_tool_cst.md for the claim under test."