Fix missing log_level propagation in Turn.execute_internal/6

[bwittenbrook3]

Jido.Exec.run/4 defaults its log_level threshold to :info when none is provided in opts, causing :notice-level "Executing ..." lines to fire on every tool call from the LLM turn loop. The agent strategy path correctly injects log_level via Jido.Observe.Config.action_exec_opts/2, but the jido_ai Turn module called Jido.Exec.run directly with bare exec_opts, bypassing that config entirely.

Fix: inject log_level from Jido.Observe.Config.action_log_level/0 in execute_internal/6 via Keyword.put_new/3, so explicit caller opts still take precedence while the global :jido, :telemetry config is respected for all tool executions.

Add unit tests verifying:

• Explicit log_level: :warning suppresses Executing logs via execute_module/4
• Explicit log_level: :warning suppresses Executing logs via execute/4
• Explicit log_level: :warning suppresses logs via run_tools/3
• Global :jido telemetry config is respected when no explicit opt given
• Explicit opt takes precedence over global config