fix: WASM double-X3DH bug, federated aliases, deploy tooling

WASM fix (critical):
- encrypt_key_exchange_with_id was calling x3dh::initiate a second time,
  generating a new ephemeral key that didn't match the ratchet — receiver
  always failed to decrypt. Now stores X3DH result from initiate() and
  reuses it. Added 2 protocol tests confirming the fix + the bug.
- Bumped service worker cache to wz-v2 to force browsers to re-fetch.
- Disabled wasm-opt for Hetzner builds (libc compat issue).

Federation — alias support:
- resolve_alias falls back to federation peer if not found locally
- register_alias checks peer server before allowing — globally unique aliases
- Added resolve_remote_alias() and is_alias_taken_remote() to FederationHandle

Federation — key proxy fix:
- Remote bundles no longer cached locally (stale cache caused decrypt failures)
- Local vs remote determined by device: prefix in keys DB

Client fixes:
- Self-messaging blocked ("Cannot send messages to yourself")
- /peer <self> blocked
- last_dm_peer never set to self
- /r <message> sends reply inline (switches peer + sends in one command)

Deploy tooling:
- scripts/build-linux.sh with --ship (build + deploy + destroy)
- --update-all, --status, --logs commands
- WASM rebuilt on Hetzner VM before server binary
- deploy/ directory: systemd service, federation configs, setup script
- Journald log cap (50MB, 7-day retention)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

warzone/deploy/setup.sh

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Setup script — run as root on each server.
+# Usage: ./setup.sh <mequ|kh3rad3ree>
+
+HOSTNAME="${1:-}"
+if [ -z "$HOSTNAME" ] || { [ "$HOSTNAME" != "mequ" ] && [ "$HOSTNAME" != "kh3rad3ree" ]; }; then
+  echo "Usage: $0 <mequ|kh3rad3ree>"
+  exit 1
+fi
+
+echo "=== Setting up featherChat on $HOSTNAME ==="
+
+# Create warzone user if it doesn't exist
+if ! id warzone &>/dev/null; then
+  echo "[1/4] Creating warzone user..."
+  useradd -r -m -s /bin/bash warzone
+else
+  echo "[1/4] User warzone already exists"
+fi
+
+# Create data directory
+echo "[2/4] Creating directories..."
+mkdir -p /home/warzone/data
+chown -R warzone:warzone /home/warzone
+
+# Copy binaries
+echo "[3/4] Installing binaries..."
+cp warzone-server warzone-client /home/warzone/
+chmod +x /home/warzone/warzone-server /home/warzone/warzone-client
+cp "federation-${HOSTNAME}.json" /home/warzone/federation.json
+chown warzone:warzone /home/warzone/warzone-server /home/warzone/warzone-client /home/warzone/federation.json
+
+# Install systemd service + journald log cap
+echo "[4/5] Installing systemd service..."
+cp warzone-server.service /etc/systemd/system/
+systemctl daemon-reload
+systemctl enable warzone-server
+
+echo "[5/5] Capping journal logs (50MB max, 7 day retention)..."
+mkdir -p /etc/systemd/journald.conf.d
+cp journald-warzone.conf /etc/systemd/journald.conf.d/warzone.conf
+systemctl restart systemd-journald
+# Vacuum existing logs
+journalctl --vacuum-size=50M 2>/dev/null || true
+
+echo ""
+echo "=== Done ==="
+echo "Start:   systemctl start warzone-server"
+echo "Status:  systemctl status warzone-server"
+echo "Logs:    journalctl -u warzone-server -f"
+echo "Stop:    systemctl stop warzone-server"