XERK-539: show agent + Turma version in the collapsed dashboard host header

[xerhab]

What & why

The web dashboard (turma/public/index.html) only surfaced the coding-agent version and the Turma agent version once a host card was expanded (in the .host-meta block). The Android card already shows those two facts in its collapsed header. XERK-539 asks for parity: make that info visible in the web header when the card is collapsed too.

Change

• New helper hostVerLine(a) (beside codingAgent()): returns "<coding agent> <version> · Turma <agentVersion>", reusing codingAgent()'s legacy raw-string parsing and its – unknown fallback.
• A version line under the hostname, rendered only while the card is collapsed — <span class="host-ver">, wrapped with the <h3> in a new .host-name-text flex column. When expanded it disappears and the fuller .host-meta row carries Agent/Turma as before (no duplication).
• CSS: .host-name-text (column) + .host-ver (muted 12px, word-break: break-word).

turma/public/ only; no server/agent plumbing.

Web ⇄ Android parity

This closes a gap where the web lagged Android — the Android collapsed card header already shows codingAgentLabel · Turma <ver> (FleetScreen.kt). No Android change is needed; the web is catching up to it.

Verification

• Unit: added hostVerLine cases to turma/tests/host-header.test.js (the two versions present → "Claude Code 2.1.211 · Turma 1.2.3"; neither present → "– · Turma –"). Full turma suite green (1700 pass, 1 pre-existing skip).
• QA agent verdict: PASS. Built and driven end-to-end in a real headless Chrome across desktop + 390px, light + dark, with a hub fed real heartbeats for every case:
  • Collapsed header shows the line under the hostname; agent name honored, not hardcoded (Qwen 3.0.5 · Turma 1.2.3).
  • Expanded card does not duplicate the line; .host-meta still carries Agent/Turma.
  • Legacy raw claudeVersion ("2.1.211 (Claude Code)") parses to Claude Code 2.1.211 · ….
  • Older agent missing all version fields renders "– · Turma –", no throw.
  • Version line is esc()d — XSS payload in host name/version rendered as literal escaped text, window.__XSS stayed false.
  • Collapse/expand toggle works and collapsedHosts localStorage persistence intact.
  • Layout clean on desktop; on 390px it's cramped (hostname + chip + Restart + status pill share one flex row), but with no horizontal overflow and word-boundary wrapping. QA proved this wrapping is pre-existing (the parent commit wraps identically without the version line) — this change only adds vertical height, it doesn't create or worsen it.
  • Not exercised: a live SSE version-change repaint (same hostCard() path, exercised on initial paint + reload).