fix(acp-snapshot): skip pwshOnly scenarios without pwsh and mount task tools in the pwsh composition

examples/acp-agent/tests/acp.snapshot.ts

@@ -1,5 +1,6 @@
 import { fileURLToPath } from 'node:url'
 import { readFileSync } from 'node:fs'
+import { spawnSync } from 'node:child_process'
 import { mkdir, utimes, writeFile } from 'node:fs/promises'
 import { dirname, join } from 'node:path'
 import { homedir } from 'node:os'
@@ -168,6 +169,9 @@ const SCENARIOS: Scenario[] = [
     pinsHeader: true,
     headerClass: 'pwsh',
     configPath: PWSH_CONFIG,
+    // The composition boots the real pwsh executor; hosts without a `pwsh`
+    // binary skip the run (fixtures stay guarded).
+    pwshOnly: true,
   },
   { name: 'todo-write', hasModelTurn: true, recorded: true },
   {
@@ -431,11 +435,16 @@ const SCENARIOS: Scenario[] = [
   },
 ]
 
+// Hosts without a `pwsh` binary skip the pwsh-tool-turn run (its fixtures
+// stay guarded); the probe follows the executor's own resolution.
+const hasPwsh = spawnSync('pwsh', ['-NoLogo', '-NoProfile', '-NonInteractive', '-Command', '$true'], { encoding: 'utf8' }).status === 0
+
 defineAcpSnapshotSuite({
   agent: AGENT,
   snapshotsDir: SNAPSHOTS_DIR,
   scenarios: SCENARIOS,
   mode: snapshotModeFromEnv(process.env.DSH_SNAPSHOT),
+  hasPwsh,
 })
 
 it('packed ACP fixture retains every chunk row kind without changing the logical session', () => {

examples/acp-agent/tests/pwsh.cordis.snapshot.yml

@@ -27,7 +27,7 @@
     workspaceContext: false
     skills:
       enabled: false
-    toolTasks: false
+# task_output/task_kill stay mounted so background pwsh runs are readable and killable.
     goals: false
     # The pwsh tool replaces the bundle's bash tool in this composition.
     toolBash: false

examples/acp-agent/tests/pwsh.cordis.yml

@@ -26,7 +26,7 @@
     workspaceContext: false
     skills:
       enabled: false
-    toolTasks: false
+# task_output/task_kill stay mounted so background pwsh runs are readable and killable.
     goals: false
     # The pwsh tool replaces the bundle's bash tool in this composition.
     toolBash: false

examples/acp-agent/tests/snapshots/pwsh-tool-turn/session.jsonl

@@ -15,7 +15,7 @@
 {"type":"assistant/chunk","seq":65,"time":1785655507602,"data":{"turn":1,"step":1,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}}
 {"type":"assistant/message","seq":66,"time":1785655507604,"data":{"turn":1,"step":1,"message":{"role":"assistant","content":[{"type":"reasoning","text":"The user wants me to run a PowerShell command that outputs \"PWSH_OK\" and then reply with \"DONE\"."},{"type":"tool-call","id":"call_00_oEhmLGLNsvlumiE0WkXD0511","name":"pwsh","arguments":"{\"command\": \"Write-Output PWSH_OK\", \"description\": \"Output PWSH_OK string\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-pro"},"id":"4d81cc10-507e-49a8-96f4-aa3ae5ad2eb5"},"usage":{"inputTokens":816,"outputTokens":96,"cacheReadTokens":0,"reasoningTokens":25}},"sourceEventSeqs":[6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65],"surfaceOp":"append"}
 {"type":"tool/call","seq":67,"time":1785655507605,"data":{"turn":1,"step":1,"callId":"call_00_oEhmLGLNsvlumiE0WkXD0511","name":"pwsh","arguments":"{\"command\": \"Write-Output PWSH_OK\", \"description\": \"Output PWSH_OK string\"}"}}
-{"type":"tool/result","seq":68,"time":1785655507994,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_oEhmLGLNsvlumiE0WkXD0511"},"content":[{"type":"tool-result","toolCallId":"call_00_oEhmLGLNsvlumiE0WkXD0511","content":[{"type":"text","text":"PWSH_OK\n"}],"isError":false}],"role":"user","id":"84a96d55-5bd5-46fc-ab0d-918882c504e2"}},"sourceEventSeqs":[67],"surfaceOp":"append"}
+{"type":"tool/result","seq":68,"time":1785655507994,"data":{"turn":1,"step":1,"message":{"source":{"kind":"tool","callId":"call_00_oEhmLGLNsvlumiE0WkXD0511"},"content":[{"type":"tool-result","toolCallId":"call_00_oEhmLGLNsvlumiE0WkXD0511","content":[{"type":"text","text":"PWSH_OK\r\n"}],"isError":false}],"role":"user","id":"84a96d55-5bd5-46fc-ab0d-918882c504e2"}},"sourceEventSeqs":[67],"surfaceOp":"append"}
 {"type":"step/end","seq":69,"time":1785655507994,"data":{"turn":1,"step":1}}
 {"type":"step/start","seq":70,"time":1785655508000,"data":{"turn":1,"step":2}}
 {"type":"assistant/chunk","seq":71,"time":1785655508608,"data":{"turn":1,"step":2,"chunk":{"type":"block-start","index":0,"blockType":"reasoning"}}}

examples/acp-agent/tests/snapshots/pwsh-tool-turn/system-prompt.expected.md

@@ -3,3 +3,5 @@ You are an AI agent powered by the DeepSeek Harness SDK.
 You are a concise snapshot agent working in {{cwd}}.
 
 Non-zero exits are reported as `[exit code: N]` markers; investigate failures before moving on. On Windows a killed process settles as `[exit code: 1]` without a signal marker; treat a bare exit 1 after an interruption as a termination, not a command failure.
+
+Track every background task id you start. You are notified in-session when a task finishes — do not busy-poll or sleep on one; keep working on independent steps and do not duplicate a running task's work. Before giving a final answer, collect every still-relevant task with task_output (set wait: true only when you are genuinely blocked on it), and task_kill tasks that stopped mattering.

examples/acp-agent/tests/snapshots/pwsh-tool-turn/tool-schemas.expected.json

@@ -32,6 +32,58 @@
           "description"
         ]
       }
+    },
+    {
+      "name": "task_kill",
+      "description": "Request cancellation of a running background task by task id. Returns immediately; the task settles as killed once its work actually stops.",
+      "parameters": {
+        "type": "object",
+        "properties": {
+          "task_id": {
+            "type": "string",
+            "description": "Task id returned by the tool that started the background work."
+          },
+          "reason": {
+            "type": "string",
+            "description": "Optional short reason, recorded in the log and forwarded to the task."
+          }
+        },
+        "required": [
+          "task_id"
+        ]
+      }
+    },
+    {
+      "name": "task_list",
+      "description": "List your background tasks (running and finished) with their ids, kinds, and statuses.",
+      "parameters": {
+        "type": "object",
+        "properties": {}
+      }
+    },
+    {
+      "name": "task_output",
+      "description": "Read a background task. Stream tasks return only output since the previous read; final-output tasks return their result after settlement. Every response ends with `[status: ...]`. Reads are non-blocking unless `wait: true`, which waits up to the configured cap.",
+      "parameters": {
+        "type": "object",
+        "properties": {
+          "task_id": {
+            "type": "string",
+            "description": "Task id returned by the tool that started the background work."
+          },
+          "wait": {
+            "type": "boolean",
+            "description": "Block until the task reaches a terminal status or the timeout expires. A timed-out wait returns [status: running] and leaves the task alive."
+          },
+          "timeout_ms": {
+            "type": "number",
+            "description": "Max wait in milliseconds (only meaningful with wait: true). Defaults to the configured wait timeout; capped by the configured maximum."
+          }
+        },
+        "required": [
+          "task_id"
+        ]
+      }
     }
   ],
   "changes": []