fix(mastra): move use-mastra skill to skills/ per repo convention

The hand-written use-mastra skill was added at .agents/skills/use-mastra/
in #161, but .agents/skills/ is reserved for vendor-managed skills.sh
output tracked in skills-lock.json (see CLAUDE.md). Move it to the default
skills/ location and switch the plugin.json skills field to array form
["./skills/", "./.agents/skills/"] so both paths load. No skill content
changed.

Refs #161

Author: amondnet

plugins/mastra/.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "mastra",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "description": "Official agent skills for coding agents working with the Mastra AI framework",
   "author": {
     "name": "Mastra AI",
@@ -24,5 +24,5 @@
       ]
     }
   },
-  "skills": "./.agents/skills/"
+  "skills": ["./skills/", "./.agents/skills/"]
 }

plugins/mastra/CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## [1.3.1] - 2026-04-29
+
+
+### Bug Fixes
+
+* **mastra:** move hand-written `use-mastra` skill from `.agents/skills/` to `skills/` per repo convention. `.agents/skills/` is reserved for vendor-managed skills.sh-installed skills tracked in `skills-lock.json`. The `skills` field in `plugin.json` now uses array form `["./skills/", "./.agents/skills/"]` so both default and vendor paths load. No skill content changed.
+
 ## [1.3.0](https://github.com/pleaseai/claude-code-plugins/compare/mastra-v1.2.0...mastra-v1.3.0) (2026-04-23)