feat(#2505): Phase 4 — runtime-aware subagent dispatch (Option A; resolve-dispatch-type query) (#2525)

* feat(#2508): Phase 4 Option A — runtime-aware subagent dispatch via resolve-dispatch-type query (#2505)

* fix(#2508): prose-variant preamble (avoid scanner-tripping literals) + namedDispatch===false-only mapping

* fix(#2508): remove leftover old-preamble lines (keep prose variant only)

* fix #2508: prose-only reference file

* test #2508: regen golden install parity after workflow preamble additions

* fix #2508: remove preamble from plan-phase.md (Phase 6 capstone ceiling); regen size+golden baselines

* docs(changeset): backfill PR #2525 for Phase 4 (#2508)

gsd-core/workflows/map-codebase.md

@@ -140,6 +140,10 @@ Before spawning agents, detect whether the current runtime supports the `Agent`
 <step name="spawn_agents" condition="Agent tool is available">
 Spawn 4 parallel gsd-codebase-mapper agents.
 
+<!-- #2508 runtime-aware-dispatch -->
+
+> **Runtime-aware dispatch (#2508 Phase 4).** GSD workflows dispatch specialized subagents by role. Before dispatching on a built-in-only runtime (kimi-code — three built-ins only), resolve the role to a built-in via `gsd_run query resolve-dispatch-type --requested <role> --raw`. On named-dispatch runtimes (Claude/OpenCode/…) the role is returned unchanged; on kimi-code it maps to `coder`/`explore`/`plan` by role-suffix. The persona rides `${AGENT_SKILLS_<ROLE>}` (Phase 3) regardless. See @gsd-core/references/runtime-aware-dispatch.md.
+
 Use Agent tool with `subagent_type="gsd-codebase-mapper"`, `model="{mapper_model}"`, and `run_in_background=true` for parallel execution.
 
 **CRITICAL:** Use the dedicated `gsd-codebase-mapper` agent, NOT `Explore` or `browser_subagent`. The mapper agent writes documents directly.
@@ -407,7 +411,6 @@ Created .planning/codebase/:
 - INTEGRATIONS.md ([N] lines) - External services and APIs
 - CONCERNS.md ([N] lines) - Technical debt and issues
 
-
 ---
 
 ## ▶ Next Up — [${PROJECT_CODE}] ${PROJECT_TITLE}