fix: Register docker_stats tool in runtime

The docker_stats tool was implemented but not registered in the runtime,
so it wasn't available to agents.

Changes:
- Added docker_stats to system_tools list in runtime.rs
- Added docker_stats registration case in create_system_executor
- Exported DockerStatsTool from aof-tools lib.rs

Now agents can use:
  tools:
    - docker_stats

The tool automatically uses --no-stream flag to avoid timeouts.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: initcron

crates/aof-runtime/src/executor/runtime.rs

@@ -121,7 +121,7 @@ impl Runtime {
                 "kubectl_get", "kubectl_apply", "kubectl_delete", "kubectl_logs",
                 "kubectl_exec", "kubectl_describe",
                 // Legacy docker tools
-                "docker_ps", "docker_logs", "docker_build", "docker_run",
+                "docker_ps", "docker_stats", "docker_logs", "docker_build", "docker_run",
                 "docker_exec", "docker_images",
                 // Legacy git tools
                 "git_status", "git_diff", "git_log", "git_commit", "git_branch",
@@ -806,6 +806,9 @@ fn create_builtin_executor_for_tools(tool_names: &[String]) -> Arc<dyn ToolExecu
             "docker_ps" => {
                 registry.register(aof_tools::DockerPsTool::new());
             }
+            "docker_stats" => {
+                registry.register(aof_tools::DockerStatsTool::new());
+            }
             "docker_build" => {
                 registry.register(aof_tools::DockerBuildTool::new());
             }

crates/aof-tools/src/lib.rs

@@ -96,7 +96,7 @@ pub use tools::observability::{ObservabilityTools, PrometheusQueryTool, LokiQuer
 pub use tools::kubectl::{KubectlTools, KubectlGetTool, KubectlApplyTool, KubectlDeleteTool, KubectlLogsTool, KubectlExecTool, KubectlDescribeTool};
 
 #[cfg(feature = "docker")]
-pub use tools::docker::{DockerTools, DockerPsTool, DockerBuildTool, DockerRunTool, DockerLogsTool, DockerExecTool, DockerImagesTool};
+pub use tools::docker::{DockerTools, DockerPsTool, DockerStatsTool, DockerBuildTool, DockerRunTool, DockerLogsTool, DockerExecTool, DockerImagesTool};
 
 #[cfg(feature = "git")]
 pub use tools::git::{GitTools, GitStatusTool, GitDiffTool, GitLogTool, GitCommitTool, GitBranchTool, GitCheckoutTool, GitPullTool, GitPushTool};