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).

packages/spill/spill-policy/tests/spill-policy.spec.ts

@@ -204,6 +204,7 @@ describe('outer Code Mode failure capture', () => {
       name: 'run_code',
       arguments: {
         code: 'console.log("HEAD-" + "x".repeat(300)); console.log("TAIL-" + "y".repeat(300)); return "unreachable";',
+        description: 'Print oversized head and tail lines',
       },
       agent: agent as never,
     })