fix(examples): restore the tui-demo pre-boot TTY refusal and stabilize the PTY smoke

The built-bin fail-loud test needs the TTY refusal before Loader boot (a
compose-time throw is logged per-entry, not rethrown); the PTY driver drops
COLORTERM so a developer's truecolor shell cannot flip the banner to the
gradient path mid-assertion; the scripted fixture persists raw JSONL so the
smoke's system-prompt inspection can read the log.

examples/tui-agent/tests/fixtures/tui-scripted.cordis.yml

@@ -21,6 +21,9 @@
     provider: tui-scripted
     model: tui-scripted-model
     persistenceRoot: './.sessions'
+    # The smoke's log inspection reads plain `.jsonl`; keep the scripted
+    # fixture uncompressed like the other snapshot-facing configs.
+    persistenceCompression: none
     workspaceContext:
       maxBytes: 65536
     welcome: 'scripted TUI ready.'

examples/tui-agent/tests/tui-keyless-smoke.e2e.ts

@@ -22,6 +22,10 @@ env.update({
     "COLUMNS": "100",
     "LINES": "30",
 })
+# Deterministic banner: a developer shell's COLORTERM=truecolor would switch the
+# banner to the per-letter gradient (one SGR per letter), breaking the literal
+# DEEPSEEK assertions. The gradient path has its own unit and snapshot coverage.
+env.pop("COLORTERM", None)
 if resume_session_id:
     env["RESUME_SESSION_ID"] = resume_session_id
 pid, fd = pty.fork()