Reorder community extensions table alphabetically

Per Copilot review feedback and EXTENSION-PUBLISHING-GUIDE.md

Author: Barry Gervin

extensions/README.md

@@ -72,10 +72,10 @@ The following community-contributed extensions are available in [`catalog.commun
 
 | Extension | Purpose | URL |
 |-----------|---------|-----|
-| V-Model Extension Pack | Enforces V-Model paired generation of development specs and test specs with full traceability | [spec-kit-v-model](https://github.com/leocamello/spec-kit-v-model) |
 | Cleanup Extension | Post-implementation quality gate that reviews changes, fixes small issues (scout rule), creates tasks for medium issues, and generates analysis for large issues | [spec-kit-cleanup](https://github.com/dsrednicki/spec-kit-cleanup) |
 | Retrospective Extension | Post-implementation retrospective with spec adherence scoring, drift analysis, and human-gated spec updates | [spec-kit-retrospective](https://github.com/emi-dm/spec-kit-retrospective) |
 | Spec Sync | Detect and resolve drift between specs and implementation. AI-assisted resolution with human approval | [spec-kit-sync](https://github.com/bgervin/spec-kit-sync) |
+| V-Model Extension Pack | Enforces V-Model paired generation of development specs and test specs with full traceability | [spec-kit-v-model](https://github.com/leocamello/spec-kit-v-model) |
 
 ## Adding Your Extension