Merge remote-tracking branch 'origin/master' into feat/todo-multi-in-progress

# Conflicts:
#	examples/acp-agent/tests/snapshots/escalation-approved/session.jsonl
#	examples/acp-agent/tests/snapshots/escalation-rejected/session.jsonl
#	examples/acp-agent/tests/snapshots/fs-escalation-approved/session.jsonl
#	examples/acp-agent/tests/snapshots/hook-cc-pretool-ask/session.jsonl
#	examples/headless-agent/tests/snapshots/advanced-toolchain/session.jsonl

examples/acp-agent/tests/snapshots/code-mode-turn/system-prompt.expected.md

@@ -30,7 +30,7 @@ Pass `run_code` the body of an async TypeScript function (erasable syntax only
 
 - Call tools as `await tools.name(args)` — quoted access for exotic names: `tools["my-tool"](args)`. Every call resolves to the tool's typed canonical JSON value. Tool arguments must be lossless JSON.
 - A FAILED tool call rejects with `ToolCallError`, whose `toolName` identifies the failed tool and whose `message` is human-readable — `try/catch` it to handle and continue.
-- Calls execute sequentially, even under `Promise.all`.
+- Independent read-only calls MAY overlap under `Promise.all` (safe calls run concurrently; mutating calls run alone, in submission order). Sequence dependent work with `await`.
 - Emit results with `return` and/or `console.log(...)`. ONLY what you print or return comes back to you — intermediate tool results never enter the conversation, so extract just what you need.
 
 The available tools:

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

@@ -9,10 +9,15 @@
           "code": {
             "type": "string",
             "description": "The program: the body of an async TypeScript function."
+          },
+          "description": {
+            "type": "string",
+            "description": "Clear, concise description of what this program does in active voice, 5-10 words (shown in the UI). Examples: \"Count TODO markers across packages\"; \"Read failing test and its fixture\"; \"Rename config key in every cordis.yml\"."
           }
         },
         "required": [
-          "code"
+          "code",
+          "description"
         ]
       }
     }