docs(reference): import Dune: Awakening server-manager references

Phase 2 references for the host-agent Dune adapter, moved out of volatile /tmp
into docs/reference-repos/ (per Commander). Three upstream projects, .git +
node_modules + compiled binaries stripped (16MB source). Nested AI-instruction
files (.claude/, CLAUDE.md) removed so they don't pollute Corrosion sessions.

- icehunter/    dune-admin (Go+React) — 4 control planes; SETUP_DOCKER.md is the
                closest analog to our agent's Dune docker control plane (compose
                lifecycle, docker logs, RabbitMQ-via-exec, dune Postgres schema)
- adainrivers/  Rust/Tauri desktop — SSH+k8s BattleGroup control, maintenance
                daemon, in-game admin console (Rust idiom reference)
- the4rchangel/ Node web UI replacing battlegroup.bat — matches the Commander's
                Hyper-V self-host path + game-config schema

See docs/reference-repos/README.md for the full index + how we use each.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/reference-repos/icehunter/cmd/dune-admin/motd.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"context"
+	"log"
+	"strings"
+)
+
+// ── Message of the Day (#163/#167/#135) ─────────────────────────────────────
+// A configurable in-game message whispered to a player every time they join the
+// server (a per-session trigger, distinct from the welcome package's once-per-
+// version grant message). Join detection is the presenceTracker diffing the
+// online set across scanner ticks; the send reuses the proven GM-whisper path.
+
+// motdDefaultPlayerName is substituted for {player} when a joining account has
+// no resolvable character name, so the message is never malformed.
+const motdDefaultPlayerName = "traveler"
+
+// renderMOTD substitutes message placeholders with the joining player's details.
+// v1 supports {player} (the character name). Kept pure so it is trivially
+// testable and free of side effects.
+func renderMOTD(template string, acc welcomeAccount) string {
+	name := strings.TrimSpace(acc.CharacterName)
+	if name == "" {
+		name = motdDefaultPlayerName
+	}
+	return strings.ReplaceAll(template, "{player}", name)
+}
+
+// motdWhisper is one resolved message to send: recipient account, sender
+// identity (blank → seeded GM persona), and the rendered text.
+type motdWhisper struct {
+	accountID    int64
+	sourcePlayer string
+	message      string
+}
+
+// motdWhispersForJoins builds the whispers to send for a set of join events
+// under the given MOTD config. Returns nil when MOTD is disabled or the message
+// is blank, so the caller never sends an empty message. Pure (no side effects).
+func motdWhispersForJoins(joins []welcomeAccount, enabled bool, message, sourcePlayer string) []motdWhisper {
+	if !enabled || strings.TrimSpace(message) == "" {
+		return nil
+	}
+	out := make([]motdWhisper, 0, len(joins))
+	for _, acc := range joins {
+		out = append(out, motdWhisper{
+			accountID:    acc.AccountID,
+			sourcePlayer: sourcePlayer,
+			message:      renderMOTD(message, acc),
+		})
+	}
+	return out
+}
+
+// welcomePresence is the join-detection state for the MOTD feature. Touched only
+// by the single welcome-scanner goroutine, so it needs no synchronisation.
+var welcomePresence = newPresenceTracker()
+
+// runMOTDOnJoin observes the current online set, then whispers the configured
+// MOTD to each newly-joined player. Called from the scanner tick with the
+// online snapshot already fetched (shared with the package scan).
+func runMOTDOnJoin(ctx context.Context, rt welcomePackageRuntime, online []welcomeAccount) {
+	joins := welcomePresence.observe(online)
+	for _, m := range motdWhispersForJoins(joins, rt.motdEnabled, rt.motdMessage, rt.motdSourcePlayer) {
+		if err := sendWelcomeWhisper(ctx, m.accountID, m.sourcePlayer, m.message); err != nil {
+			log.Printf("motd: whisper to account %d failed: %v", m.accountID, err)
+		}
+	}
+}