feat(tools): run_code description param + native-parity dispatch logging + web code-mode seam

run_code gains a required bash-style description parameter: presentCall
titles the card with it and moves the program to rawInput, so every
surface gets a readable label. tool/code-dispatch now logs each
sub-call's complete content/isError (the tool/result vocabulary),
replacing the bounded resultSummary and deleting the summarize/cwd
machinery — a UI renders sub-calls through the identical path as native
results. The dsh config tree mounts the worker code runtime and reads
DSH_TOOLS_MODE (temporary seam until per-session mode selection lands).

Session format stays v0 (pre-release churn). Code-mode ACP/TUI fixtures
re-recorded; TUI presenter pin refreshed; catalogs regenerated. Keyless
web smoke pins the code-mode wire contract (tools=[run_code] + SDK
prompt section).

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

@@ -1,6 +1,6 @@
 You are an AI agent powered by the DeepSeek Harness SDK.
 
-You are a coding assistant powered by the deepseek-v4-flash model. Your working directory is {{cwd}}.
+You are a coding assistant powered by the deepseek-v4-pro model. Your working directory is {{cwd}}.
 
 Verify your work by running the code or tests. Keep answers brief and factual.
 

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"
         ]
       }
     }