feat(platform): close AI expense value loop

Add tenant-safe value, telemetry, connector, commercial, and production-readiness foundations.

server/tests/runtime_chat_testkit.py

@@ -0,0 +1,79 @@
+from __future__ import annotations
+
+from app.services.runtime_chat import RuntimeChatOperationContext, RuntimeChatService
+from app.services.runtime_chat_attempts import RuntimeChatAttemptPermit
+
+
+class RecordingAttemptObserver:
+    def __init__(self, timeline: list[str] | None = None) -> None:
+        self.permits = []
+        self.completed = []
+        self.failures = []
+        self.timeline = timeline
+
+    def on_permit(self, event):
+        self.permits.append(event)
+        if self.timeline is not None:
+            self.timeline.append(f"permit:{event.identity.attempt}")
+        return None
+
+    def on_completed(self, event) -> None:
+        self.completed.append(event)
+        if self.timeline is not None:
+            self.timeline.append(
+                f"completed:{event.identity.attempt}:{event.outcome}"
+            )
+
+    def on_observer_failure(self, failure) -> None:
+        self.failures.append(failure)
+
+
+class FailingCompletionObserver(RecordingAttemptObserver):
+    def on_completed(self, event) -> None:
+        super().on_completed(event)
+        raise RuntimeError("completion observer unavailable")
+
+
+class FailingPermitObserver(RecordingAttemptObserver):
+    def on_permit(self, event):
+        super().on_permit(event)
+        raise RuntimeError("permit observer unavailable")
+
+
+class DenyingAttemptObserver(RecordingAttemptObserver):
+    def on_permit(self, event):
+        super().on_permit(event)
+        return RuntimeChatAttemptPermit(
+            allowed=False,
+            reason="tenant quota exhausted",
+        )
+
+
+def build_operation_context() -> RuntimeChatOperationContext:
+    return RuntimeChatOperationContext(
+        tenant_id="tenant-runtime-chat",
+        operation_id="operation-runtime-chat-001",
+        run_id="run-runtime-chat-001",
+        invocation_seq=7,
+        attempt_scope="unit-test-completion",
+    )
+
+
+def patch_single_slot(
+    monkeypatch,
+    service: RuntimeChatService,
+    *,
+    provider: str,
+    model: str,
+) -> None:
+    monkeypatch.setattr(
+        service,
+        "_load_chat_slot",
+        lambda slot: {
+            "slot": slot,
+            "provider": provider,
+            "endpoint": "https://example.com/v1",
+            "model": model,
+            "apiKey": "secret",
+        },
+    )