v0.55.2

Changed

• The CLI card and the Account card are now one "Agent" card. It
  reads top to bottom as: which agent, whether its command was found
  (with the install button when not), whether it is signed in, the
  sign-in method, the sign-in buttons, and a closed-by-default
  "Advanced (executable / command)" foldout holding the former CLI
  fields, which opens itself while the command is not found. One
  "Reconnect" button replaces "Re-detect", "Reconnect now" and the ACP
  "Reconnect". The "Diagnostics" card is renamed "CLI output (stderr)".
  Settings values and the reconnect-banner behavior are unchanged.
  Design notes:
  docs/design-notes/2026-09-17-account-card-agent-picker-and-acp-init.md
  (the picker's move out of the collapsed CLI card, the first step) and
  docs/design-notes/2026-09-17-agent-card-merge.md (the merge).
• "API key authentication" (Claude Code only) and "Auth method id"
  (ACP only) are now one "Sign-in method" row whose shape follows the
  selected agent: Claude Code offers "Auto (leave it to the CLI)" /
  "Subscription only", an ACP agent takes its authenticate method id.
  Switching to an ACP agent no longer leaves the Claude hint line
  behind. Design note 2026-09-17-agent-card-merge.md, section 3.

Fixed

• "Connected with an API key (acp)" no longer shows under a
  "Subscription only" picker. After switching from an ACP agent back to
  Claude Code, the Account card read the ACP bridge's synthesized
  system/init (which carried apiKeySource: "acp") as Claude API-key
  billing until Claude's own init arrived. An init an ACP bridge produced
  is never counted as Claude API-key auth, and the bridge now reports
  apiKeySource: "none". Design note
  docs/design-notes/2026-09-17-account-card-agent-picker-and-acp-init.md.