init: arcadia-admin — admin webapp for arcadia-core, cloned from vibespace

Initial commit. Spun up via the docs/STARTER.md recipe: cp from vibespace,
reset git, rename package, set brand to "Arcadia Admin" with Shield icon
in app/lib/identity.ts.

Inherits the full Crema sibling-lib wiring including @crema/arcadia-client
(typed HTTP + Phoenix Channels realtime against arcadia-core) and
@crema/arcadia-auth-ui (login/signup/password-reset/2FA forms). The /login
route already renders <LoginForm>; <ArcadiaProvider> in app/root.tsx reads
VITE_ARCADIA_URL (default localhost:4000) and VITE_ARCADIA_TENANT (default
"default").

CLAUDE.md and README rewritten to frame this as the admin app for
arcadia-core. docs/STARTER.md removed — arcadia-admin is a leaf consumer,
not a downstream starter.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

start.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+cd "$(dirname "$0")"
+
+PID_FILE=".demo.pid"
+LOG_FILE=".demo.log"
+
+if [ -f "$PID_FILE" ]; then
+  existing="$(cat "$PID_FILE")"
+  if [ -n "$existing" ] && kill -0 "$existing" 2>/dev/null; then
+    echo "crema-app-aifirst-template already running (pid $existing)"
+    exit 0
+  fi
+  rm -f "$PID_FILE"
+fi
+
+nohup npm run dev >"$LOG_FILE" 2>&1 &
+pid=$!
+echo "$pid" >"$PID_FILE"
+disown "$pid" 2>/dev/null || true
+
+echo "crema-app-aifirst-template started (pid $pid) — logs: $LOG_FILE"