terminal tool_started cards used to fall through to the generic
ToolStartedRenderer (a raw JSON dump of the args — a wall of quoted strings for
a command or input). Add an action-aware started renderer, mirroring the result
renderer and the filesystem started renderer:

- Title: → terminal <action>.
- run: the command as a shell prompt in accent (the headline) + optional cwd.
- open: terminal name (accent) + description + background + command preview.
- close/status: terminal name. send_input: name + input preview.
- list: empty body (no per-call headline; the result card carries the table).

Registered before ToolStartedRenderer (first accepting wins).

Tests: started accepts gating + run/open/close/send_input/list cards;
render_plain covers the borderless reading-mode path. Full suite: 1000 passed,
1 skipped.