defer optional telemetry dependencies in perception graph

src/k1link/perception/graph.py

@@ -8,14 +8,15 @@ from contextlib import AbstractContextManager
 from dataclasses import dataclass, replace
 from queue import Empty, Full, Queue
 from threading import Event, Lock, Thread
-from typing import TypeVar, cast
+from typing import TYPE_CHECKING, TypeVar, cast
 
-from k1link.compute.pipeline_telemetry import (
-    PipelineStageOutcome,
-    PipelineTelemetryEmitter,
-    PipelineTelemetryIdentity,
-    PipelineTelemetrySink,
-)
+if TYPE_CHECKING:
+    from k1link.compute.pipeline_telemetry import (
+        PipelineStageOutcome,
+        PipelineTelemetryEmitter,
+        PipelineTelemetryIdentity,
+        PipelineTelemetrySink,
+    )
 
 from .baseline import BASELINE_PROFILE_ID, BASELINE_SOURCE_ID
 from .contracts import (
@@ -763,6 +764,8 @@ class ReferencePerceptionGraphV1:
     def _run_emitter(self) -> PipelineTelemetryEmitter | None:
         if self.telemetry_identity is None or self.telemetry_sink is None:
             return None
+        from k1link.compute.pipeline_telemetry import PipelineTelemetryEmitter
+
         return PipelineTelemetryEmitter(
             identity=self.telemetry_identity,
             sink=self.telemetry_sink,
@@ -772,6 +775,8 @@ class ReferencePerceptionGraphV1:
     def _frame_emitter(self, packet: SourcePacket) -> PipelineTelemetryEmitter | None:
         if self.telemetry_identity is None or self.telemetry_sink is None:
             return None
+        from k1link.compute.pipeline_telemetry import PipelineTelemetryEmitter
+
         identity = replace(
             self.telemetry_identity,
             request_id=packet.envelope.frame_id,