agent terminal: coherence pass

layout
- unified prefix-column for every row kind: padding-left + negative
  text-indent so the glyph (→ ← · ◆ ✓ ✗ ⌁ !) sits in the same column
  whether the row is flat or a <details>. wraps hang under the body,
  not under the glyph.
- expandable rows drop the directional glyph from their summary text;
  the ▸/▾ disclosure marker from CSS sits in the prefix column instead,
  and the row's colour still carries cyan = outbound, muted = inbound.
- turn-start / turn-end de-weighted: bold/margin/tint dropped, the
  coloured left rule alone marks the boundary.

note classification
- stderr lines render orange with a `!` glyph (was muted `·`)
- operator-initiated notes (cancel/compact/model/new-session) render
  mauve italic (was muted `·` indistinguishable from harness chatter)
- catch-all .sys row escalates to orange `!` so unrecognised stream-json
  shapes surface for follow-up instead of hiding in muted noise

message-bearing rows
- send / ask / answer tool_use rich renderers default-open with the
  body inline; new ask + answer renderers (previously fell through to
  the generic JSON dump). recv tool_result also default-open, keyed by
  tracking tool_use_id → name across the stream so we know which
  result came from which tool.
- assistant text rows render markdown.
- bodies use vendored marked v4.0.2 (hive-fr0nt::MARKED_JS); falls
  back to plain text when the asset doesn't load.

extra-mcp tool pretty-print
- generic args formatter replaces the raw JSON dump for unknown tools
  (single-string field → `name k: "v"`; single dict / multi-field →
  trimmed `k: v · k: v …` summary)

dashboard .live .msgrow gets a text-indent: 0 reset so the new
hanging-indent metrics from TERMINAL_CSS don't leak into the flex-grid
broker rows.

hive-c0re/assets/dashboard.css

@@ -668,6 +668,10 @@ summary:hover { color: var(--purple); }
   align-items: baseline;
   gap: 0.5em;
   padding: 0.1em 0;
+  /* Override the per-agent-terminal's hanging-indent metrics from
+     TERMINAL_CSS — the dashboard's broker rows are flex grids, not
+     glyph-prefixed text, and don't want the prefix column. */
+  text-indent: 0;
 }
 .live .msgrow .msg-body {
   flex: 1 1 0;