diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index 3c52efce8..374dd8774 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -291,6 +291,7 @@ Templates contain the workflows, tips, and examples that require human judgment.
 | `{{UX_PRINCIPLES}}` | `resolvers/design.ts` | User behavioral foundations (scanning, satisficing, goodwill reservoir, trunk test) for /design-html, /design-shotgun, /design-review, /plan-design-review |
 | `{{GBRAIN_CONTEXT_LOAD}}` | `resolvers/gbrain.ts` | Brain-first context search with keyword extraction, health awareness, and data-research routing. Injected into 10 brain-aware skills. Suppressed on non-brain hosts. |
 | `{{GBRAIN_SAVE_RESULTS}}` | `resolvers/gbrain.ts` | Post-skill brain persistence with entity enrichment, throttle handling, and per-skill save instructions. 8 skill-specific save formats. |
+| `{{FOREGROUND_DISPATCH_NOTE}}` | `resolvers/constants.ts` | Canonical `run_in_background: false` guidance for every synchronous Agent-tool subagent dispatch (subagents run in the background by default since Claude Code v2.1.198). Single source of truth; carriers are pinned per file by `test/run-in-background-guidance.test.ts`. |
 
 This is structurally sound — if a command exists in code, it appears in docs. If it doesn't exist, it can't appear.
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 17305c0ad..ba2d5e0d5 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -459,6 +459,7 @@ When Conductor creates a new workspace, `bin/dev-setup` runs automatically. It d
 - **`.env` propagates across worktrees.** Set it once in the main repo, all Conductor workspaces get it.
 - **`.claude/skills/` is gitignored.** The symlinks never get committed.
 - **Never write raw `ln -snf` in `setup`.** Every link site in `setup` MUST route through the `_link_or_copy SRC DST` helper near the `IS_WINDOWS` detection. The helper preserves `ln -snf` on Unix and switches to `cp -R` / `cp -f` on Windows without Developer Mode, where plain `ln -snf` produces frozen file copies that don't refresh on `git pull`. `test/setup-windows-fallback.test.ts` enforces this with a static invariant — a single raw `ln` call outside the helper body fails CI.
+- **Synchronous subagent dispatches must state the flag.** Claude Code runs Agent-tool subagents in the background by default (since v2.1.198), so any template step that dispatches a subagent and consumes its output must carry `run_in_background: false`. Use the `{{FOREGROUND_DISPATCH_NOTE}}` placeholder (`scripts/resolvers/constants.ts`) instead of hand-writing the guidance, and add the generated carrier file to `GENERATED_WITH_GUIDANCE` in `test/run-in-background-guidance.test.ts` in the same commit — its structural scanner fails CI on any generated dispatch imperative that lacks the flag.
 
 ## Testing your changes in a real project