The desktop app already had solid session streaming, permission, and tool-rendering flows, but extension setup still forced users into manual forms or external shell work. This change adds an Install Center in Settings that reuses the session chat pipeline for natural-language installs, adds installer-specific guidance for plugin and skill URLs, and includes an agent-browser E2E script for real UI validation.
Constraint: Must reuse the existing session/chat execution path instead of introducing a second install runtime
Constraint: Plugin installs need real CLI commands while skill installs may come from published install commands on third-party pages
Rejected: Separate terminal-only install surface | duplicates session UX and weakens permission/tool visibility
Rejected: Pure form-based installer expansion | too much friction for plugin, MCP, and skill onboarding
Confidence: medium
Scope-risk: moderate
Reversibility: clean
Directive: Keep installer prompts aligned with the actual CLI install surfaces; do not let the installer fall back to slash-command syntax inside Bash
Tested: cd desktop && bun run lint
Tested: Real UI automation via agent-browser for Telegram plugin install flow through Settings > Install, verified Plugins page shows telegram enabled
Tested: Real UI automation via agent-browser for ui-ux-pro-max skill install flow through Settings > Install, verified ~/.claude/skills/ui-ux-pro-max and Skills page visibility
Not-tested: Full e2e-install-center-agent-browser.sh script as a single uninterrupted green run after the latest stability tweaks
