fix(subagent): remove permission.question=deny override that caused zombie sessions

Child session creation was injecting permission: { question: 'deny' } which
conflicted with OpenCode's child session permission handling, causing subagent
sessions to hang with 0 messages after creation (zombie state).

Remove the permission override from all session creators (BackgroundManager,
sync-session-creator, call-omo-agent) and rely on prompt-level tool restrictions
(tools.question=false) to maintain the intended policy.

Closes #1711

src/tools/call-omo-agent/session-creator.test.ts

@@ -0,0 +1,50 @@
+import { describe, expect, test } from "bun:test"
+
+import { createOrGetSession } from "./session-creator"
+import { _resetForTesting, subagentSessions } from "../../features/claude-code-session-state"
+
+describe("call-omo-agent createOrGetSession", () => {
+  test("creates child session without overriding permission and tracks it as subagent session", async () => {
+    // given
+    _resetForTesting()
+
+    const createCalls: Array<unknown> = []
+    const ctx = {
+      directory: "/project",
+      client: {
+        session: {
+          get: async () => ({ data: { directory: "/parent" } }),
+          create: async (args: unknown) => {
+            createCalls.push(args)
+            return { data: { id: "ses_child" } }
+          },
+        },
+      },
+    }
+
+    const toolContext = {
+      sessionID: "ses_parent",
+      messageID: "msg_parent",
+      agent: "sisyphus",
+      abort: new AbortController().signal,
+    }
+
+    const args = {
+      description: "test",
+      prompt: "hello",
+      subagent_type: "explore",
+      run_in_background: true,
+    }
+
+    // when
+    const result = await createOrGetSession(args as any, toolContext as any, ctx as any)
+
+    // then
+    expect(result).toEqual({ sessionID: "ses_child", isNew: true })
+    expect(createCalls).toHaveLength(1)
+    const createBody = (createCalls[0] as any)?.body
+    expect(createBody?.parentID).toBe("ses_parent")
+    expect(createBody?.permission).toBeUndefined()
+    expect(subagentSessions.has("ses_child")).toBe(true)
+  })
+})

src/tools/call-omo-agent/session-creator.ts

@@ -1,5 +1,6 @@
 import type { CallOmoAgentArgs } from "./types"
 import type { PluginInput } from "@opencode-ai/plugin"
+import { subagentSessions } from "../../features/claude-code-session-state"
 import { log } from "../../shared"
 
 export async function createOrGetSession(
@@ -38,9 +39,6 @@ export async function createOrGetSession(
       body: {
         parentID: toolContext.sessionID,
         title: `${args.description} (@${args.subagent_type} subagent)`,
-        permission: [
-          { permission: "question", action: "deny" as const, pattern: "*" },
-        ],
       } as any,
       query: {
         directory: parentDirectory,
@@ -65,6 +63,7 @@ Original error: ${createResult.error}`)
 
     const sessionID = createResult.data.id
     log(`[call_omo_agent] Created session: ${sessionID}`)
+    subagentSessions.add(sessionID)
     return { sessionID, isNew: true }
   }
 }

src/tools/call-omo-agent/subagent-session-creator.test.ts

@@ -0,0 +1,47 @@
+import { describe, expect, test } from "bun:test"
+
+import { resolveOrCreateSessionId } from "./subagent-session-creator"
+import { _resetForTesting, subagentSessions } from "../../features/claude-code-session-state"
+
+describe("call-omo-agent resolveOrCreateSessionId", () => {
+  test("tracks newly created child session as subagent session", async () => {
+    // given
+    _resetForTesting()
+
+    const createCalls: Array<unknown> = []
+    const ctx = {
+      directory: "/project",
+      client: {
+        session: {
+          get: async () => ({ data: { directory: "/parent" } }),
+          create: async (args: unknown) => {
+            createCalls.push(args)
+            return { data: { id: "ses_child_sync" } }
+          },
+        },
+      },
+    }
+
+    const args = {
+      description: "sync test",
+      prompt: "hello",
+      subagent_type: "explore",
+      run_in_background: false,
+    }
+
+    const toolContext = {
+      sessionID: "ses_parent",
+      messageID: "msg_parent",
+      agent: "sisyphus",
+      abort: new AbortController().signal,
+    }
+
+    // when
+    const result = await resolveOrCreateSessionId(ctx as any, args as any, toolContext as any)
+
+    // then
+    expect(result).toEqual({ ok: true, sessionID: "ses_child_sync" })
+    expect(createCalls).toHaveLength(1)
+    expect(subagentSessions.has("ses_child_sync")).toBe(true)
+  })
+})

src/tools/call-omo-agent/subagent-session-creator.ts

@@ -1,5 +1,6 @@
 import type { PluginInput } from "@opencode-ai/plugin"
 import { log } from "../../shared"
+import { subagentSessions } from "../../features/claude-code-session-state"
 import type { CallOmoAgentArgs } from "./types"
 import type { ToolContextWithMetadata } from "./tool-context-with-metadata"
 
@@ -63,5 +64,6 @@ Original error: ${createResult.error}`,
 
 	const sessionID = createResult.data.id
 	log(`[call_omo_agent] Created session: ${sessionID}`)
+	subagentSessions.add(sessionID)
 	return { ok: true, sessionID }
 }

src/tools/call-omo-agent/subagent-session-prompter.ts

@@ -13,6 +13,7 @@ export async function promptSubagentSession(
 				tools: {
 					...getAgentToolRestrictions(options.agent),
 					task: false,
+					question: false,
 				},
 				parts: [{ type: "text", text: options.prompt }],
 			},

src/tools/delegate-task/sync-session-creator.ts

@@ -13,9 +13,6 @@ export async function createSyncSession(
     body: {
       parentID: input.parentSessionID,
       title: `${input.description} (@${input.agentToUse} subagent)`,
-      permission: [
-        { permission: "question", action: "deny" as const, pattern: "*" },
-      ],
     } as any,
     query: {
       directory: parentDirectory,