feat: rename bugfix-ship/requirement-flow to short-ship/long-ship with shared ship records

short-ship and long-ship share one ship-id record under .pouch/ship/<id>/.
specifier writes PRDs into spec/; delivery-loop appends evidence pointers.
Old names stay as deprecation stubs so existing installs keep working.

skills/specifier/templates/current.template.yaml

@@ -1,6 +1,16 @@
-featureId: <feature-id>
-currentRevision: v001
-status: review
-prd: prd-v001.html
-approvedRevision: null
-reviews: review.yaml
+# 已并入 ship current.yaml 的 spec 字段。新建需求请用 ship 模板，不要单独写这份文件。
+# 迁移旧 .pouch/specifier/features/<id>/current.yaml 时按此对照：
+#   featureId          -> shipId
+#   currentRevision    -> spec.revision
+#   status             -> spec.specStatus
+#   prd                -> spec.prd（路径加上 spec/ 前缀）
+#   approvedRevision   -> spec.approvedRevision
+#   reviews            -> spec.reviews
+shipId: <ship-id>
+spec:
+  revision: v001
+  specStatus: review
+  prd: spec/prd-v001.html
+  approvedRevision: null
+  reviews: spec/review.yaml
+  handoff: null