fix(builder): point version.mk at ~/.pouch after merging main

Keep ~/.skills as a lookup fallback so existing checkouts still resolve
version.sh.

skills/builder/references/contract.md

@@ -81,7 +81,7 @@ manage-release，不猜测下一个正式 SemVer。正式 tag 由 manage-release
 `scripts/version.mk`：
 
 ```makefile
-include $(HOME)/.skills/skills/builder/scripts/version.mk
+include $(HOME)/.pouch/skills/builder/scripts/version.mk
 ```
 
 ## 3. 发布环境变量

skills/builder/scripts/version.mk

@@ -4,7 +4,7 @@
 # Command-line / environment VERSION= is passed as --version (official X.Y.Z
 # only when HEAD exact-matches that tag). Unset or empty VERSION is derived.
 #
-#   include $(HOME)/.skills/skills/builder/scripts/version.mk
+#   include $(HOME)/.pouch/skills/builder/scripts/version.mk
 
 _builder_scripts_dir := $(dir $(lastword $(MAKEFILE_LIST)))
 
@@ -16,11 +16,14 @@ ifeq ($(BUILDER_VERSION_SH),)
     BUILDER_VERSION_SH := $(wildcard $(BUILDER_SKILL_DIR)/scripts/version.sh)
   endif
 endif
+ifeq ($(BUILDER_VERSION_SH),)
+  BUILDER_VERSION_SH := $(wildcard $(HOME)/.pouch/skills/builder/scripts/version.sh)
+endif
 ifeq ($(BUILDER_VERSION_SH),)
   BUILDER_VERSION_SH := $(wildcard $(HOME)/.skills/skills/builder/scripts/version.sh)
 endif
 ifeq ($(BUILDER_VERSION_SH),)
-  $(error version.sh not found; set BUILDER_SKILL_DIR or clone skills to ~/.skills)
+  $(error version.sh not found; set BUILDER_SKILL_DIR or clone pouch to ~/.pouch)
 endif
 
 ifeq ($(filter command line environment,$(origin VERSION)),)