Initial commit: split VNOX monorepo into VNOX-Server

Unified server binary (vnox-serverd) combining:
- Gateway (TCP, auth, channels, sessions, SQLite)
- Voice-node (UDP relay, Opus, jitter buffer)

Standalone gateway (vnox-gateway) and voice-node (vnox-voice-node) preserved as sub-crates.

gateway/src/handler/guild/crud.rs

@@ -0,0 +1,124 @@
+use anyhow::Result;
+use tokio::net::TcpStream;
+use tracing::debug;
+
+use crate::{
+    domain::session,
+    net::{io, state::State},
+    proto::{GuildCreatePayload, GuildInfo, PacketId, SessionCrypto, to_payload},
+};
+
+use super::send_err;
+
+pub async fn handle_guild_create(
+    stream: &mut TcpStream,
+    seq: &mut u32,
+    session_id: &str,
+    payload: &[u8],
+    crypto: &SessionCrypto,
+    state: &State,
+) -> Result<()> {
+    let req: GuildCreatePayload = serde_json::from_slice(payload)?;
+    let sess = session::get(&state.sessions, session_id)
+        .await
+        .ok_or_else(|| anyhow::anyhow!("session not found"))?;
+
+    if req.name.len() < 2 || req.name.len() > 100 {
+        send_err(
+            stream,
+            seq,
+            crate::proto::ErrorCode::InvalidPacket,
+            "guild name must be 2-100 chars",
+            crypto,
+        )
+        .await?;
+        return Ok(());
+    }
+
+    let guild_id = state.storage.create_guild(&sess.user_id, &req.name).await?;
+    let guild = state
+        .storage
+        .get_guild(&guild_id)
+        .await?
+        .ok_or_else(|| anyhow::anyhow!("guild not found after create"))?;
+
+    let info = GuildInfo {
+        id: guild.id.clone(),
+        owner_id: guild.owner_id,
+        name: guild.name,
+        member_count: guild.member_count,
+        created_at: guild.created_at,
+    };
+
+    io::send_encrypted(
+        stream,
+        PacketId::GuildCreate,
+        seq,
+        &to_payload(&info),
+        crypto,
+    )
+    .await?;
+
+    debug!(
+        "guild: {} created {} (owner={})",
+        sess.nickname, guild_id, sess.user_id
+    );
+    Ok(())
+}
+
+pub async fn handle_guild_delete(
+    stream: &mut TcpStream,
+    seq: &mut u32,
+    session_id: &str,
+    payload: &[u8],
+    crypto: &SessionCrypto,
+    state: &State,
+) -> Result<()> {
+    #[derive(serde::Deserialize)]
+    struct Req {
+        guild_id: String,
+    }
+    let req: Req = serde_json::from_slice(payload)?;
+    let sess = session::get(&state.sessions, session_id)
+        .await
+        .ok_or_else(|| anyhow::anyhow!("session not found"))?;
+
+    let guild = state
+        .storage
+        .get_guild(&req.guild_id)
+        .await?
+        .ok_or_else(|| anyhow::anyhow!("guild not found"))?;
+    if guild.owner_id != sess.user_id {
+        send_err(
+            stream,
+            seq,
+            crate::proto::ErrorCode::PermissionDenied,
+            "only owner can delete guild",
+            crypto,
+        )
+        .await?;
+        return Ok(());
+    }
+
+    state.storage.delete_guild(&req.guild_id).await?;
+    state
+        .storage
+        .append_audit_log(
+            &req.guild_id,
+            &sess.user_id,
+            "GUILD_DELETE",
+            None,
+            None,
+            None,
+        )
+        .await?;
+    io::send_encrypted(
+        stream,
+        PacketId::GuildDelete,
+        seq,
+        &to_payload(&serde_json::json!({"guild_id": req.guild_id})),
+        crypto,
+    )
+    .await?;
+    Ok(())
+}