Update numbering within the future roadmap

docs/roadmap/future.md

@@ -6,7 +6,7 @@ plans, or release commitments. Adopting a candidate requires an explicit design
 decision and a separate plan. Significant architectural exclusions and their rationale belong
 in ADRs; this document does not maintain a list of rejected proposals.
 
-## 3. Recursive body merging for identified records
+## 1. Recursive body merging for identified records
 
 Status: deferred. The implemented
 [collection policy](../config.md#strict-document-composition) uses `upsert` to
@@ -20,7 +20,7 @@ presence and ordering, and how provenance, history, sensitivity, and resource
 context follow partially retained records. Any change requires a new decision and
 implementation plan; this entry does not alter current upsert behavior.
 
-## 4. Required version declarations for selected sources
+## 2. Required version declarations for selected sources
 
 Status: deferred. PromptKit requested a way to require version declarations on
 a selected subset of source files while permitting other fragments to omit them.
@@ -56,7 +56,7 @@ compatible version or replace final configuration validation.
   behavior for absent optional inputs and preserve source-local diagnostics,
   inspection evidence, and existing sensitivity handling.
 
-## 5. Performance experiments
+## 3. Performance experiments
 
 Status: deferred pending evidence. The completed performance audit identified
 four internal optimization candidates for separate investigation:
@@ -84,7 +84,7 @@ evidence are preserved in Git history at `8e91a2b` under `docs/roadmap/`.
 - What cache lifetime and concurrency design would make schema reuse worthwhile
   without excessive retained memory?
 
-## 6. Public path comparison
+## 4. Public path comparison
 
 Status: deferred pending a concrete consumer need. This preserves A2 from the
 completed API review at `68400ff:docs/roadmap/review.md`.