Complete DFG-9 application decision

SLICE_HISTORY.md

@@ -1,5 +1,37 @@
 # Completed slices
 
+## DFG-9 controlled application decision
+
+### Decision
+
+- Retained manual canonical integration as the permanent DocForge 0.x policy.
+- Added no application command to the library, CLI, or MCP server.
+- Kept project builders, tests, Git, deployment, and publication under developer or project-owner
+  control.
+- Required a new approved gate with measured multi-project evidence before canonical application
+  can be reconsidered.
+
+### Evidence
+
+- DFG-8 produced one real content-only AssetForge proposal and one manual chapter replacement.
+- Validation, conflicts, diffs, previews, and stale-source handling were already automated.
+- Manual integration completed without an error, lost work, or meaningful repeated cost.
+- Automating the remaining step would require canonical writers, developer authorization, atomic
+  rollback, failure recovery, and project-format ownership that the current evidence does not
+  justify.
+- Existing exact-surface MCP tests prohibit application tools, and proposal tests preserve
+  canonical source bytes.
+
+### Limits
+
+- DocForge does not apply, commit, push, build, deploy, or publish canonical changes.
+- Reopening the decision requires a separately approved, versioned contract and cannot add MCP
+  canonical application.
+
+### Next gate
+
+No further DFG gate is planned. Continue measured adoption through project-owned integrations.
+
 ## DFG-0 contract freeze and DFG-1 standalone read-only core
 
 ### Changed