cli: avoid data-dir initialization for version; create db parent dirs; redact generated passwords in CLI output

- Prevent 'nx9-wg version' from creating data directories by avoiding database initialization.
- Create parent directories when an explicit --database path is provided.
- Redact printed generated administrator passwords; announce file path or redact instead.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

config.example.toml

@@ -0,0 +1,41 @@
+# ==============================================================================
+# NX9 WireGuard - Configuration File Example
+# ==============================================================================
+
+# Directory where persistent database and state files are stored
+data_dir = "/var/lib/nx9-wg"
+
+# Bind address and port for the Axum REST API and WebSocket daemon
+bind_address = "127.0.0.1:8080"
+
+# Application log level (trace, debug, info, warn, error)
+log_level = "info"
+
+# Inactivity expiration for administrator web sessions in hours
+session_expiry_hours = 24
+
+# Interval in seconds between background kernel reconciliation cycles
+reconciliation_interval_secs = 60
+
+# ── Backup Configuration ──────────────────────────────────────────────────────
+[backup]
+# Directory where backup snapshots and manifests are generated
+dir = "/var/lib/nx9-wg/backups"
+
+# Maximum number of automated backup snapshots to retain
+max_count = 10
+
+# Optional cron schedule for automated database backups (e.g. "0 2 * * *" for 02:00 UTC)
+# schedule = "0 2 * * *"
+
+# ── Initial Bootstrap Configuration (Optional) ──────────────────────────────
+# Used only during initial startup when no administrator exists in the database.
+# Ignored once the single administrator identity is provisioned in SQLite.
+# [bootstrap]
+# admin_username = "admin"
+# admin_password = "ChangeMeToASecurePassword123!"
+
+# ── Static Admin Definition (Optional Override) ───────────────────────────────
+# [admin]
+# username = "admin"
+# password_hash = "$argon2id$v=19$m=19456,t=2,p=1$..."