🎯 fix: MCP Tool Misclassification from Action Delimiter Collision (#12512)

* fix: prevent MCP tools with `_action` in name from being misclassified as OpenAPI action tools

Add `isActionTool()` helper that checks for the `_action_` delimiter
while guarding against cross-delimiter collision with `_mcp_`. Replace
all `includes(actionDelimiter)` classification checks with the new
helper across backend and frontend.

* test: add coverage for MCP/action cross-delimiter collision

Verify that `isActionTool` correctly rejects MCP tool names containing
`_action` and that `loadAgentTools` does not filter them based on
`actionsEnabled`. Add ToolIcon and definitions test cases.

* fix: simplify isActionTool to handle all MCP name patterns

- Use `!toolName.includes('_mcp_')` instead of checking only after the
  first `_action_` occurrence, which missed MCP tools with `_action_` in
  the middle of their name (e.g. `get_action_data_mcp_myserver`).
- Reference `Constants.mcp_delimiter` value via a local const to avoid
  circular import from config.ts, with a comment explaining why.
- Remove dead `actionDelimiter` import from definitions.ts.
- Replace double-filter with single-pass partition in loadToolsForExecution.
- Add test for mid-name `_action_` collision case.

* fix: narrow MCP exclusion to delimiter position in isActionTool

Only reject when `_mcp_` appears after `_action_` (the MCP suffix
position). `_mcp_` before `_action_` is part of the operationId and
is valid — e.g. `sync_mcp_state_action_api---example---com` is a
legitimate action tool whose operationId happens to contain `_mcp_`.

* fix: document positional _mcp_ guard and known RFC-invalid domain limitation

Expand JSDoc on isActionTool to explain the action/MCP format
disambiguation and the theoretical false negative for non-RFC-compliant
domains containing `_mcp_`. Add test documenting this known edge case.

api/server/services/ToolService.js

@@ -31,6 +31,7 @@ const {
   imageGenTools,
   EModelEndpoint,
   EToolResources,
+  isActionTool,
   actionDelimiter,
   ImageVisionTool,
   openapiToFunction,
@@ -490,7 +491,7 @@ async function loadToolDefinitionsWrapper({ req, res, agent, streamId = null, to
     if (tool === Tools.web_search) {
       return checkCapability(AgentCapabilities.web_search);
     }
-    if (tool.includes(actionDelimiter)) {
+    if (isActionTool(tool)) {
       return actionsEnabled;
     }
     if (!areToolsEnabled) {
@@ -871,7 +872,7 @@ async function loadAgentTools({
     } else if (tool === Tools.web_search) {
       includesWebSearch = checkCapability(AgentCapabilities.web_search);
       return includesWebSearch;
-    } else if (tool.includes(actionDelimiter)) {
+    } else if (isActionTool(tool)) {
       return actionsEnabled;
     } else if (!areToolsEnabled) {
       return false;
@@ -978,7 +979,7 @@ async function loadAgentTools({
 
   agentTools.push(...additionalTools);
 
-  const hasActionTools = _agentTools.some((t) => t.includes(actionDelimiter));
+  const hasActionTools = _agentTools.some((t) => isActionTool(t));
   if (!hasActionTools) {
     return {
       toolRegistry,
@@ -1237,8 +1238,11 @@ async function loadToolsForExecution({
     ? [...new Set([...requestedNonSpecialToolNames, ...ptcOrchestratedToolNames])]
     : requestedNonSpecialToolNames;
 
-  const actionToolNames = allToolNamesToLoad.filter((name) => name.includes(actionDelimiter));
-  const regularToolNames = allToolNamesToLoad.filter((name) => !name.includes(actionDelimiter));
+  const actionToolNames = [];
+  const regularToolNames = [];
+  for (const name of allToolNamesToLoad) {
+    (isActionTool(name) ? actionToolNames : regularToolNames).push(name);
+  }
 
   if (regularToolNames.length > 0) {
     const includesWebSearch = regularToolNames.includes(Tools.web_search);