refactor: rename envVars to env and remove example field from TPMJS spec

- Rename TpmjsEnvVarSchema to TpmjsEnvSchema
- Rename envVars field to env throughout codebase
- Remove example field from TpmjsMinimalSchema (no longer required)
- Update all documentation (spec page, publish page, HOW_TO_PUBLISH_A_TOOL.md)
- Update example tool package.json
- Simplify minimal tier requirements to only category and description

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

packages/tools/createBlogPost/package.json

@@ -35,7 +35,6 @@
   "tpmjs": {
     "category": "text-analysis",
     "description": "Creates structured blog posts with customizable frontmatter, content sections, and SEO metadata. Supports multiple output formats including Markdown and MDX.",
-    "example": "const post = await createBlogPost({ title: 'My First Post', author: 'John Doe', content: 'Hello World!', tags: ['intro', 'blog'] });",
     "parameters": [
       {
         "name": "title",