feat(logging): close audit gaps — SDK records, proxy tracebacks, CLI/docker/posthog

Five gaps from the post-implementation audit, closed:

1. **SDK logger captured.** The openai-agents SDK uses
   ``logging.getLogger("openai.agents")`` for its own lifecycle events
   (Runner.run starts, tool dispatch, model retries, exceptions).
   Previous setup only attached handlers to the ``strix`` root, so
   SDK-internal events were dropped. Tracked-roots tuple now covers
   both, with the same FileHandler/StreamHandler/Filter chain.

2. **Proxy tool exception tracebacks.** Every ``@function_tool`` in
   ``strix/tools/proxy/tools.py`` returns a JSON error to the LLM via
   the ``_err(name, exc)`` helper. The tracebacks were silently
   formatted away — the LLM saw the message, the human reading the
   log saw nothing. ``_err`` now emits ``logger.exception(...)``
   covering all five tools at once.

3. **CLI bootstrap.** ``strix/interface/main.py`` had its module
   ``logger`` removed by the previous commit and was emitting nothing.
   Restored, plus log lines for env validation, docker check, LLM
   warm-up, and image pull (debug for already-present, info for
   pull, exception for failures).

4. **Docker client.** ``strix/runtime/docker_client.py`` had no
   logger. Container creation now logs caps + exposed ports at DEBUG
   and the resulting container id at INFO.

5. **PostHog telemetry.** ``strix/telemetry/posthog.py`` had no
   logger. Now logs send success/failure at DEBUG, version-detection
   failures at DEBUG, and disabled-skip at DEBUG (so the log shows
   when telemetry is off, instead of being silent about it).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

strix/runtime/docker_client.py

@@ -17,6 +17,7 @@ re-merging the parent body. Track upstream for an injection hook.
 
 from __future__ import annotations
 
+import logging
 import uuid
 from typing import Any
 
@@ -32,6 +33,9 @@ from docker.models.containers import Container  # type: ignore[import-untyped, u
 from docker.utils import parse_repository_tag  # type: ignore[import-untyped, unused-ignore]
 
 
+logger = logging.getLogger(__name__)
+
+
 class StrixDockerSandboxClient(DockerSandboxClient):
     """``DockerSandboxClient`` subclass that injects Strix-required capabilities.
 
@@ -100,4 +104,16 @@ class StrixDockerSandboxClient(DockerSandboxClient):
         extra_hosts = create_kwargs.setdefault("extra_hosts", {})
         extra_hosts["host.docker.internal"] = "host-gateway"
 
-        return self.docker_client.containers.create(**create_kwargs)
+        logger.debug(
+            "Creating sandbox container: image=%s caps=%s exposed_ports=%s",
+            image,
+            cap_add,
+            list(exposed_ports),
+        )
+        container = self.docker_client.containers.create(**create_kwargs)
+        logger.info(
+            "Sandbox container created: id=%s image=%s",
+            container.short_id if hasattr(container, "short_id") else "?",
+            image,
+        )
+        return container