fix(mosaic): wire constrained recovery runtime boundaries

packages/mosaic/framework/tools/lease-broker/receipt_observer.py

@@ -1,9 +1,11 @@
 #!/usr/bin/env python3
 """Trusted latest-assistant-message observer boundary for receipt promotion.
 
-Runtime adapters must implement ``observe_latest_assistant_message`` directly:
-Claude selects the exact latest assistant entry and Pi selects ``message_end``.
-The broker accepts no observed message through its request protocol.
+Production adapters deliver finalized assistant content over the daemon-owned
+observer socket after the daemon authenticates their peer against the broker's
+kernel-anchored session identity. The broker request protocol never accepts
+assistant-message content. Claude supplies its latest assistant entry; Pi
+supplies finalized assistant content at ``message_end``.
 """
 
 from __future__ import annotations
@@ -26,7 +28,7 @@ class ReceiptObserver(Protocol):
 
 
 class UnavailableReceiptObserver:
-    """Production-safe default until a runtime adapter injects an observer."""
+    """Fail-closed only for direct unit construction without daemon transport."""
 
     def observe_latest_assistant_message(
         self,
@@ -38,6 +40,31 @@ class UnavailableReceiptObserver:
         return None
 
 
+class RuntimeReceiptObserver:
+    """Daemon-owned production observer populated only by authenticated adapters."""
+
+    def __init__(self) -> None:
+        self._messages: dict[tuple[str, str, int], str] = {}
+
+    def record_latest_assistant_message(
+        self,
+        session_id: str,
+        runtime: str,
+        runtime_generation: int,
+        message: str,
+    ) -> None:
+        self._messages[(session_id, runtime, runtime_generation)] = message
+
+    def observe_latest_assistant_message(
+        self,
+        session_id: str,
+        runtime: str,
+        runtime_generation: int,
+        _binding: dict[str, object],
+    ) -> str | None:
+        return self._messages.get((session_id, runtime, runtime_generation))
+
+
 class TestReceiptObserver:
     """Deterministic controlled observer used only by byte-build tests."""
 
@@ -60,7 +87,7 @@ class TestReceiptObserver:
 
 
 class FileTestReceiptObserver:
-    """Private fixture-file observer for isolated out-of-process test drivers."""
+    """Private fixture-file observer for isolated out-of-process test drivers only."""
 
     def __init__(self, path: Path) -> None:
         self.path = path