feat: prefill agent-edit modal, Ctrl+Enter submits modals, improve README

- AgentFormModal: sync form state to current agent values when the modal
  opens (useEffect on open/agent), so edit always shows the agent's
  current name, description, website, icon URL, and max-pending value.
- Modal: add optional onSubmit prop; Ctrl+Enter (or ⌘+Enter) fires it,
  covering AgentFormModal, DecisionModal, and both Settings modals
  (disable 2FA, delete account) without breaking textarea newlines or
  text-input behaviour.
- README: substantially expanded — purpose, capabilities, architecture,
  quick-start with Docker Compose, dev setup, testing, agent integration
  (OpenClaw, generic MCP, REST), and privacy notes.
- TODO.md: remove three completed items (prefill modal, Ctrl+Enter, human
  readme).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

TODO.md

@@ -9,14 +9,11 @@ Thoughts:
 - Able to click on a agent either on home, agents list or in a request to show the agents past requests and overall actions from the list but moved over into a new page with a back button to return to the previous page.
 - Show QR for 2fa
 - invalid dates on admin action notifications
-- pre fill data on agent edit modal
 - overall ux improvements
 - Fix popup for passwordmanagers filling in 2fa code on settings page
-- ctrl enter submits modals (all)
 - better repo rules for agents
 - Nicer statistics on the dashboard
 - Instance Notice popup that popups up on every session (like a cookie notice), content by admins, dismissable
 - Instance Disabled message & setting for admins to set a message for when the instance is disabled, and a setting to allow users to see the message when the instance is disabled. (users can only delte or download their data when the instance is disabled)
 - Data Hoster notice for footer when people host an instance for other people to use, content by admins, not dismissable footer only notice, all pages
-- mobile friendly improvements
-- human readme
+- mobile friendly improvements