feat: Code Mode — the registry's mode config, the SDK codegen, and the run_code bridge

The dsh-tools half of the Code Mode RFC (its fourth, final change): the
registry gains its first config — mode: native | code | both — and OWNS how
its tools reach the model. 'code' contributes exactly one wire tool,
run_code, plus a lazy tools:sdk prompt section declaring every other tool
as a generated TypeScript API (jsonSchemaToTs: total over the defineTool
subset, unknown degradation, lexicographic byte-identical rendering);
'both' ships both representations; 'native' is byte-for-byte the old
behavior. Non-native modes fail every assembly loudly without a
typescript-language ctx.codeRuntime.

run_code's dispatch bridge: JSON-normalizes each binding argument before
dispatch (what dispatches is what the tool/code-dispatch event logs — the
append can never fail on payload shape; BigInt/circulars reject that one
call), serializes all program tool calls through a per-run queue (even
Promise.all — no concurrency-safety metadata yet), routes every sub-call
through tools/pre-execute → tools/post-execute (a deny rejects the
program-side promise), drops sub-call additionalContext (no safe outlet
mid-run; pinned), owns a run-scoped abort that follows the outer signal in
and fires on settlement (in-flight sub-dispatch aborted, queued abandoned,
queue drained before returning), and converts a failed run into
CodeRunFailedError → a structured isError carrying kind + captured logs.
tool/code-dispatch joins SessionEventMap by declaration merging (log-only;
deriveMessages ignores it).

The composed surface: the tools config forwards through agent-core and
both app packages; examples/code-agent + demo:code run the worker runtime
under mode code (keyless boot smoke + a with-key e2e proving the collapsed
[run_code] header, the dispatch events, and the file the program wrote);
two new snapshot scenarios (code-mode-turn, both-mode-turn) record the SDK
section, collapsed header, dispatch events, and result card — each its own
header-pinning class (the harness gains per-scenario config overlays and
per-class pins). Catalogs, graphs, cookbook, hooks-bridge notes, and the
RFC (moved to implemented/, restructured to decision-era headings) updated
in the same change.

examples/acp-agent/code-mode.cordis.yml

@@ -0,0 +1,29 @@
+# Code Mode RECORD overlay: the live acp-agent tree (./cordis.yml) with two
+# load-time patches — the app entry's config gains `tools: { mode: code }`
+# (the registry offers exactly one wire tool, run_code, plus the generated
+# TypeScript SDK prompt section) and the worker-thread code runtime joins the
+# tree as `ctx.codeRuntime`. The dsh-acp-agent bin boots this file when the
+# snapshot harness records the code-mode scenarios; DSH_SNAPSHOT=replay swaps
+# it for the sibling code-mode.cordis.snapshot.yml. A config patch REPLACES
+# the entry's whole config, so the base entry's fields are restated verbatim.
+- id: base
+  name: '@cordisjs/plugin-include'
+  config:
+    path: ./cordis.yml
+    patches:
+      - id: acp-agent
+        name: '@deepseek-ai/dsh-acp-agent'
+        config:
+          model: deepseek-v4-flash
+          persistenceRoot: !!js process.env.DSH_SNAPSHOT_SESSIONS_ROOT ?? './.sessions'
+          tools:
+            mode: code
+          persona: |
+            You are a coding assistant powered by the {{model}} model. Your working
+            directory is {{cwd}}.
+
+            Verify your work by running the code or tests. Keep answers brief and
+            factual.
+      - insert:
+          - id: code-runtime
+            name: '@deepseek-ai/dsh-code-runtime-worker'