fix: smaller release blockers

[krisztianfekete]

Fixes the live view issues found with kagent harness agents.

• A failed agent turn with no model call now counts as a failed turn instead of disappearing.
• Repeated calls to the same tool each show their own result.
• Sessions sort by start time.
• Sessions without message content get a badge and cannot become the EvalSet. The Inspector pairs turns by position, like scoring does.
• The empty state shows the OTLP endpoints (/api/config now returns the receiver ports).
• Annotation queues show the agent name.
• Kubernetes example: a Collector filter that drops kagent TaskStore spans so long turns stay under the per trace span limit, a kagent version table, and commands to send prompts from the CLI. Collector configs use the current exporter names.
• openai-agents raised to 0.19+ (openai 2.53 broke 0.13).