homepage redesign + docs cleanup + agent prompting (#540)

* homepage redesign + docs cleanup + agent prompting improvements

- rewrote hero section: new tagline, responsive font sizing with clamp(),
  extracted shared constants for copy management
- added feature screenshots (shell isolation, github permissions, mcp tools,
  agent browser) and ensured consistent image sizing
- reworked feature section mobile layout: caption-style descriptions, bigger
  h3s, image padding
- made CTA buttons visible on all breakpoints (stacked on mobile, row on md+)
- reorganized docs/tools.mdx into single table with category dividers,
  simplified tool descriptions
- added markdown image syntax instruction to agent system prompt
- fixed InfoPopover overflow on small screens
- misc: InlineCode proportional sizing, OnboardingCard updates, shell/security
  doc improvements

Made-with: Cursor

* update pnpm-lock.yaml for agent-browser 0.25.4

Made-with: Cursor

agents/opentoad.ts

@@ -4,7 +4,6 @@
  * transparently wraps OpenCode with a security layer:
  * - bash: "deny" via OPENCODE_CONFIG_CONTENT (agent cannot shell out)
  * - OPENCODE_PERMISSION: filesystem sandbox — deny all external paths except /tmp
- * - untrusted .opencode/plugins/ and .opencode/tools/ deleted before launch
  * - MCP ShellTool provides restricted shell (filtered env, no secrets)
  * - MCP server injected alongside project config (not replacing)
  * - ASKPASS handles git auth separately (token never in subprocess env)