Merge origin/master: Code Mode composed with agent scopes

Master advanced 11 commits mid-merge (the Code Mode registry integration:
mode config, run_code, the tools:sdk section, the ACP run_code cards and
unified demos). The fusion makes Code Mode scope-aware end to end:

- wireSchemas(scope): the mode-aware wire contribution is computed from the
  CALLING SCOPE's visible set (scoped tools join, shadowing and restrictions
  apply) and feeds the {schemas, knownNames} provider protocol.
- knownNames under the mode collapse: a per-scope RESTRICTION is runtime
  state, so the universe stays pre-restriction (a restricted-away tool in
  toolOrder is a normal absence) — but the MODE collapse is deployment
  config, so under mode 'code' the universe is [run_code] and a toolOrder
  naming a native tool fails every assembly loud (master's tested decision,
  kept).
- The tools:sdk section renders per assembly CONTEXT: the SDK declares
  exactly the calling agent's callable set, using the section-text provider
  signature this branch already had.
- run_code bindings enumerate schemas(exec.agent) — a program can bind
  exactly what its prompt promised; sub-dispatches already threaded
  exec.agent through registry.execute, so scoped resolution and carriers
  flow unchanged.
- dsh-tools declares both sides' new deps (dsh-scope + dsh-session);
  lockfile and all generated catalogs/graphs/api-catalog regenerated.

Gates green on the merged tree: typecheck, lint, per-file 100% coverage
(2710 tests), snapshots (41), doc-sync, module graph, build, hygiene, demo
smoke.

docs/rfc/INDEX.md

@@ -10,7 +10,6 @@ Generated by `pnpm run gen-rfc-index` from the RFC tree — never edit by hand;
 |---|---|
 | [Agent Client Protocol (ACP) support — drive the coding agent from external editors](proposed/feature/2026-06-14-acp-agent-client-protocol.md) | 2026-06-14 |
 | [Multiplex concurrent ACP sessions over one connection](proposed/feature/2026-06-14-acp-multi-session.md) | 2026-06-14 |
-| [Code Mode — the model writes TypeScript against the tool registry](proposed/feature/2026-06-15-code-mode.md) | 2026-06-15 |
 | [Pre-tool input rewrite — a consistent design](proposed/feature/2026-06-30-pre-tool-input-rewrite.md) | 2026-06-30 |
 | [Claude Code and Codex subagent backends (out-of-process delegation to external coding agents)](proposed/feature/2026-07-07-claude-code-and-codex-subagent-backends.md) | 2026-07-07 |
 
@@ -50,6 +49,7 @@ Generated by `pnpm run gen-rfc-index` from the RFC tree — never edit by hand;
 
 | Title | First proposed |
 |---|---|
+| [Code Mode — the model writes TypeScript against the tool registry](implemented/feature/2026-06-15-code-mode.md) | 2026-06-15 |
 | [Filesystem tool schemas — model-facing read/write/edit shapes](implemented/feature/2026-06-17-filesystem-tool-schemas.md) | 2026-06-17 |
 | [Rich ACP bash rendering — the terminal card via the `_meta` convention](implemented/feature/2026-06-18-acp-terminal-and-tool-rendering.md) | 2026-06-18 |
 | [Compaction as a capability seam (abstract contract + basic backend)](implemented/feature/2026-06-18-compaction-capability-seam.md) | 2026-06-18 |