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

.agents/skills/lib_py/agents/adapters/claude.py

@@ -40,6 +40,10 @@ class ClaudeAgentAdapter(BaseAgentAdapter):
     def input_rule_pattern(self) -> str:
         return '─{10,}'
 
+    @property
+    def modal_tokens(self) -> Optional[str]:
+        return 'Try the new fullscreen renderer\\?'
+
     def artifact_path(self, uuid: str, ctx: DiscoveryContext) -> str:
         return f"{ctx.claude_dir}/{ctx.ws_key}/{uuid}.jsonl"