feat(logging): log full content - prompts, responses, tool I/O

- Log full message content instead of just hash
- Log full tool input arguments
- Log full tool output/results
- Add model info to session and token events

No privacy restrictions for internal monitoring.

assets/oh-my-opencode.schema.json

@@ -78,7 +78,8 @@
           "prometheus-md-only",
           "start-work",
           "sisyphus-orchestrator",
-          "todo-codebase-compaction"
+          "todo-codebase-compaction",
+          "usage-logging"
         ]
       }
     },