release: bump apple-dev-skills to v5.1.4

Why:
- publish the strengthened structure-swift-sources contract and richer file-header workflow as a patch release
- align the maintainer package, packaged plugin metadata, and lockfile version surfaces

Verification:
- uv run scripts/validate_socket_metadata.py
- (cd plugins/apple-dev-skills && uv run pytest)

Author: gaelic-ghost

.codex-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "apple-dev-skills",
-  "version": "5.1.3",
+  "version": "5.1.4",
   "description": "Apple development workflows for Codex and Claude Code, including DocC authoring and review guidance.",
   "author": {
     "name": "Gale",

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "apple-dev-skills-maintainer"
-version = "5.1.3"
+version = "5.1.4"
 description = "Maintainer tooling for the apple-dev-skills repository"
 requires-python = ">=3.9"
 dependencies = []