New SDK control-protocol requests for host-rendered dialogs

What

• Several new @internal SDK control-request/response schema pairs were added: get_status (terminal /status rows as text), export_conversation (the plain text /export would write, plus a default filename), get_skills_dialog (/skills menu rows with lock/state info), get_chrome_dialog and get_chrome_browsers/select_chrome_browser (Claude in Chrome state and browser picker), and get_sandbox_dialog (full /sandbox dialog state).
• The control-protocol client class gained matching request wrappers: getSkillsDialog, getStatus, exportConversation, getChromeDialog, getChromeBrowsers, selectChromeBrowser, and getSandboxDialog.
• The host-bridge connection handler gained matching request subtypes, each guarded by a connection check and dynamically importing dialog-builder helpers.
• All of these now return an explicit "not available in a cloud-hosted session" rejection when called in a cloud-hosted session, matching the existing behavior for get_memory_dialog.

Why This lets an external host built on the Agent SDK render the CLI's built-in dialogs — status, export, skills, Chrome, sandbox — with its own UI instead of the terminal's widgets, while making sure these terminal-specific dialogs correctly refuse to run in cloud-hosted sessions where they don't apply.