fix(profiling): improve error handling in reset_stage_profiling and update snapshot documentation

Co-authored-by: Copilot <copilot@github.com>

Author: lxsaah

.vscode/mcp.json

@@ -10,7 +10,7 @@
             "args": [
                 "run",
                 "--manifest-path",
-                "/aimdb_ws/aimdb/tools/aimdb-mcp/Cargo.toml",
+                "${workspaceFolder}/tools/aimdb-mcp/Cargo.toml",
                 "--",
                 "--socket",
                 "/tmp/aimdb-demo.sock"

aimdb-core/src/profiling/info.rs

@@ -50,7 +50,7 @@ impl StageProfilingInfo {
 
 impl RecordProfilingMetrics {
     /// Returns a serializable snapshot of every registered stage's metrics,
-    /// ordered sources → taps → links → transforms.
+    /// ordered sources → taps → links.
     pub fn snapshot(&self) -> Vec<StageProfilingInfo> {
         let mut out = Vec::new();
         for (kind, stages) in [

tools/aimdb-mcp/src/tools/profiling.rs

@@ -116,17 +116,15 @@ pub async fn reset_stage_profiling(args: Option<Value>) -> McpResult<Value> {
             "reset": true,
             "message": "Stage profiling counters reset on all records.",
         })),
-        Err(e) => {
-            // Most likely the server was built without the `profiling` feature.
-            let msg = e.to_string();
-            if msg.contains("method_not_found") || msg.contains("Unknown method") {
-                Ok(json!({
-                    "reset": false,
-                    "message": "The target instance does not support profiling.reset (built without the `profiling` feature?).",
-                }))
-            } else {
-                Err(McpError::Client(e))
-            }
+        Err(aimdb_client::ClientError::ServerError { ref code, .. })
+            if code == "method_not_found" =>
+        {
+            // The server was built without the `profiling` feature.
+            Ok(json!({
+                "reset": false,
+                "message": "The target instance does not support profiling.reset (built without the `profiling` feature?).",
+            }))
         }
+        Err(e) => Err(McpError::Client(e)),
     }
 }