opentui(phase3): launcher integration — HERMES_TUI_ENGINE dual-engine

hermes --tui launches the native OpenTUI engine (Bun) when
HERMES_TUI_ENGINE=opentui (env) or display.tui_engine=opentui (config);
Ink stays the default and the shipping path is untouched.

- _resolve_tui_engine() (env > config > ink); refuses opentui on
  Windows/Termux (no Bun) -> falls back to ink with a notice.
- _make_opentui_argv() -> [bun, src/entry.real.tsx] (no build step).
- _bun_bin() with HERMES_BUN override.
- Branch at top of _make_tui_argv BEFORE _ensure_tui_node (Bun-only host
  must not bootstrap Node).
- Gate _launch_tui NODE_OPTIONS/--max-old-space-size on engine==ink (Bun
  is JSC; the V8 flag errors/ignores).

Verified end-to-end via tmux: real hermes --tui -> Bun -> OpenTUI ->
real Python gateway streamed a real reply. No-flag default still ink.

website/scripts/prebuild.mjs

@@ -31,7 +31,6 @@ const scriptDir = dirname(fileURLToPath(import.meta.url));
 const websiteDir = resolve(scriptDir, "..");
 const extractScript = join(scriptDir, "extract-skills.py");
 const llmsScript = join(scriptDir, "generate-llms-txt.py");
-const cronBlueprintsScript = join(scriptDir, "extract-automation-blueprints.py");
 const outputFile = join(websiteDir, "static", "api", "skills.json");
 const unifiedIndexFile = join(websiteDir, "static", "api", "skills-index.json");
 const UNIFIED_INDEX_URL =
@@ -139,7 +138,3 @@ if (!existsSync(extractScript)) {
 
 // 2) llms.txt + llms-full.txt — agent-friendly docs entrypoints. Non-fatal.
 runPython(llmsScript, "generate-llms-txt.py");
-
-// 3) automation-blueprints-index.json — Automation Blueprints catalog page. Non-fatal; the page
-//    renders an empty state if the generator can't run.
-runPython(cronBlueprintsScript, "extract-automation-blueprints.py");