🛂 fix: Enforce Actions Capability Gate Across All Event-Driven Tool Loading Paths (#12252)

* fix: gate action tools by actions capability in all code paths

Extract resolveAgentCapabilities helper to eliminate 3x-duplicated
capability resolution. Apply early action-tool filtering in both
loadToolDefinitionsWrapper and loadAgentTools non-definitions path.
Gate loadActionToolsForExecution in loadToolsForExecution behind an
actionsEnabled parameter with a cache-based fallback. Replace the
late capability guard in loadAgentTools with a hasActionTools check
to avoid unnecessary loadActionSets DB calls and duplicate warnings.

* fix: thread actionsEnabled through InitializedAgent type

Add actionsEnabled to the loadTools callback return type,
InitializedAgent, and the initializeAgent destructuring/return
so callers can forward the resolved value to loadToolsForExecution
without redundant getEndpointsConfig cache lookups.

* fix: pass actionsEnabled from callers to loadToolsForExecution

Thread actionsEnabled through the agentToolContexts map in
initialize.js (primary and handoff agents) and through
primaryConfig in the openai.js and responses.js controllers,
avoiding per-tool-call capability re-resolution on the hot path.

* test: add regression tests for action capability gating

Test the real exported functions (resolveAgentCapabilities,
loadAgentTools, loadToolsForExecution) with mocked dependencies
instead of shadow re-implementations. Covers definition filtering,
execution gating, actionsEnabled param forwarding, and fallback
capability resolution.

* test: use Constants.EPHEMERAL_AGENT_ID in ephemeral fallback test

Replaces a string guess with the canonical constant to avoid
fragility if the ephemeral detection heuristic changes.

* fix: populate agentToolContexts for addedConvo parallel agents

After processAddedConvo returns, backfill agentToolContexts for
any agents in agentConfigs not already present, so ON_TOOL_EXECUTE
for added-convo agents receives actionsEnabled instead of falling
back to a per-call cache lookup.

api/server/controllers/agents/openai.js

@@ -265,6 +265,7 @@ const OpenAIChatCompletionController = async (req, res) => {
           toolRegistry: primaryConfig.toolRegistry,
           userMCPAuthMap: primaryConfig.userMCPAuthMap,
           tool_resources: primaryConfig.tool_resources,
+          actionsEnabled: primaryConfig.actionsEnabled,
         });
       },
       toolEndCallback,