fix(tui): establish 2-tier readiness model, modal/hint token separation, and adapter modal contracts

- Separate TUI dialog detection into blocking gate layer (_MAM_MODAL_TOKENS) and recovery layer (_MAM_HINT_TOKENS) to eliminate idle dialog starvation
- Add modal_tokens contract across agent adapters (claude, cline) with dynamic scope facts resolution in send_keys_safe
- Implement fail-closed resolution for ambiguous same-kind panes (R-1) and enforce WORKSPACE_ROOT export (R-2)
- Preserve session on TUI readiness timeout when PID is alive for diagnostics
- Add comprehensive test suite in tests/test_c1_tui_readiness.py and adapter contract assertions in test_a4

tests/test_a4_adapter_contract.py

@@ -84,6 +84,22 @@ def test_adapter_required_properties():
         assert adapter.delegate_agent_key == delk
         assert adapter.identity_cache_fields == cache_f
 
+
+def test_adapter_modal_tokens_contract():
+    """F-8: Verify adapter-level modal_tokens contract (T-2d)."""
+    expected_modal = {
+        'claude': 'Try the new fullscreen renderer\\?',
+        'cline': 'Select API Provider|Enter API Key|Select an API provider|API Provider|Cline API key',
+        'agy': None,
+        'hermes': None,
+        'grok': None,
+    }
+    for agent, expected in expected_modal.items():
+        adapter = get_adapter(agent)
+        assert adapter is not None
+        assert adapter.modal_tokens == expected, f"modal_tokens mismatch for {agent}"
+
+
 def test_facts_bridge_eval_contract():
     import subprocess, sys
     from pathlib import Path