fix(docs): align frontmatter titles with H1 headings

- sdk-runtime: 'Plugin SDK Runtime' -> 'Plugin Runtime Helpers'
- sdk-testing: 'SDK Testing' -> 'Plugin Testing'
- sdk-setup: 'Plugin SDK Setup' -> 'Plugin Setup and Config'

docs/plugins/sdk-runtime.md

@@ -1,5 +1,5 @@
 ---
-title: "Plugin SDK Runtime"
+title: "Plugin Runtime Helpers"
 sidebarTitle: "Runtime Helpers"
 summary: "api.runtime -- the injected runtime helpers available to plugins"
 read_when:

docs/plugins/sdk-setup.md

@@ -1,5 +1,5 @@
 ---
-title: "Plugin SDK Setup"
+title: "Plugin Setup and Config"
 sidebarTitle: "Setup and Config"
 summary: "Setup wizards, setup-entry.ts, config schemas, and package.json metadata"
 read_when:

docs/plugins/sdk-testing.md

@@ -1,5 +1,5 @@
 ---
-title: "SDK Testing"
+title: "Plugin Testing"
 sidebarTitle: "Testing"
 summary: "Testing utilities and patterns for OpenClaw plugins"
 read_when: