feat: add cline/plugins entries and feature them

[saoudrizwan]

What

Adds Cline Marketplace entries for the plugins published in cline/plugins that were not yet in the marketplace, and marks every cline/plugins entry as featured.

New plugin entries:

Entry	Tagline
agent-browser	Web and Electron browser automation via the agent-browser CLI skill
agents-squad	Background subagents with presets, skills, and shared handoffs
background-terminal	Long-running shell jobs with polling and cleanup tools
branch-protector	A hook that blocks protected branch pushes unless explicitly allowed
clickhouse-data-analyst	ClickHouse data analyst skill with supporting analysis and ClickHouse sub-skills
env-blocker	A hook that blocks reads of secret .env files
gitignore-read-files-guard	A hook that blocks file access to .gitignore ignored paths
intercom-support-triage-slack	Intercom conversation triage tools for support workflows
linear	Linear SDK scripting skill for issue, project, team, cycle, and comment workflows
mac-notify	macOS notifications when a Cline run completes
nanobanana	Image generation through OpenRouter and Gemini image models
speak	Speaks completed Cline replies with ElevenLabs text to speech
typescript-lsp	TypeScript language service goto_definition support

The two plugins already in the marketplace (goal, web-search) are updated to featured: true as well, so all of them surface in featured placements.

Details

• Each entry is its own registry/plugins/<slug>/ folder with an entry.json and a generated icon.svg, following the existing convention.
• install.args is just the plugin slug (cline plugin install <slug>), matching the existing entries.
• install.env is populated for the plugins that need secrets at runtime: intercom-support-triage-slack (INTERCOM_API_TOKEN, SLACK_BOT_TOKEN, optional SLACK_CHANNEL), linear (LINEAR_API_KEY), nanobanana (OPENROUTER_API_KEY, optional IMAGE_MODEL), and speak (ELEVENLABS_API_KEY). Taglines, descriptions, and tags are drawn from each plugin's README.
• All entries are verified: true (official Cline plugins) and featured: true.

Repo URL fix

The pre-existing goal and web-search entries pointed homepage/repo at github.com/cline/cline-plugins, but the repo is actually github.com/cline/plugins. Fixed both, and all new entries use the correct cline/plugins URL.

Testing

npm run validate passes (18 entries).