feat(cli): run an analysis without questions from flags (#1127, #1133)

- --ticker, --date and --analysts answer their steps, checked as the prompts check them; --save/--no-save and --show/--no-show answer the questions after the run
- with no terminal, the run stops before it starts and names every flag or TRADINGAGENTS_* variable still needed; a missing API key and an announcement no longer wait for input
- README shows an unattended run

tests/test_rating_integrity.py

@@ -151,7 +151,7 @@ def test_the_cli_says_when_a_run_produced_no_usable_rating(monkeypatch, tmp_path
     monkeypatch.setattr(m.console, "print", lambda *a, **k: printed.append(" ".join(str(x) for x in a)))
     monkeypatch.setattr(cli_run, "display_complete_report", lambda *a, **k: None)
     monkeypatch.setattr(m.typer, "prompt", lambda *a, **k: "N")
-    monkeypatch.setattr(cli_run, "get_user_selections", lambda: {
+    monkeypatch.setattr(cli_run, "get_user_selections", lambda flags=None: {
         "ticker": "NVDA", "analysis_date": "2026-01-10",
         "analysts": [AnalystType.MARKET], "asset_type": "stock",
     })