fix(hooks): propagate sessionKey in after_tool_call context

The after_tool_call hook in handleToolExecutionEnd was passing
`sessionKey: undefined` in the ToolContext, even though the value is
available on ctx.params. This broke plugins that need session context
in after_tool_call handlers (e.g., for per-session audit trails or
security logging).

- Add `sessionKey` to the `ToolHandlerParams` Pick type
- Pass `ctx.params.sessionKey` through to the hook context
- Add test assertion to prevent regression

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/agents/pi-embedded-subscribe.handlers.tools.ts

@@ -427,7 +427,7 @@ export async function handleToolExecutionEnd(
       .runAfterToolCall(hookEvent, {
         toolName,
         agentId: undefined,
-        sessionKey: undefined,
+        sessionKey: ctx.params.sessionKey,
       })
       .catch((err) => {
         ctx.log.warn(`after_tool_call hook failed: tool=${toolName} error=${String(err)}`);

src/agents/pi-embedded-subscribe.handlers.types.ts

@@ -132,7 +132,7 @@ export type EmbeddedPiSubscribeContext = {
  */
 export type ToolHandlerParams = Pick<
   SubscribeEmbeddedPiSessionParams,
-  "runId" | "onBlockReplyFlush" | "onAgentEvent" | "onToolResult"
+  "runId" | "onBlockReplyFlush" | "onAgentEvent" | "onToolResult" | "sessionKey"
 >;
 
 export type ToolHandlerState = Pick<

src/plugins/wired-hooks-after-tool-call.e2e.test.ts

@@ -114,7 +114,9 @@ describe("after_tool_call hook wiring", () => {
     const event = firstCall?.[0] as
       | { toolName?: string; params?: unknown; error?: unknown; durationMs?: unknown }
       | undefined;
-    const context = firstCall?.[1] as { toolName?: string } | undefined;
+    const context = firstCall?.[1] as
+      | { toolName?: string; agentId?: string; sessionKey?: string }
+      | undefined;
     expect(event).toBeDefined();
     expect(context).toBeDefined();
     if (!event || !context) {
@@ -125,6 +127,7 @@ describe("after_tool_call hook wiring", () => {
     expect(event.error).toBeUndefined();
     expect(typeof event.durationMs).toBe("number");
     expect(context.toolName).toBe("read");
+    expect(context.sessionKey).toBe("test-session");
   });
 
   it("includes error in after_tool_call event on tool failure", async () => {