modules: extract fedserv-api leaf crate (protocol + service vocabulary)

Move NetEvent/NetAction/RegReply/Protocol and Sender/ServiceCtx into a
dependency-free fedserv-api crate that a module builds against. Core keeps
referring to them through re-export shims at crate::proto and
crate::engine::service, so no consumer changes. Groundwork for external
service and protocol modules.

modules/protocol/mod.rs

@@ -1,97 +1,6 @@
-// Protocol abstraction. The engine only ever sees NetEvent / NetAction; raw
-// server-to-server lines live entirely behind a Protocol impl. Adding another
-// ircd later means one new module, engine untouched.
+// Protocol layer. The normalized vocabulary (NetEvent / NetAction / RegReply)
+// and the Protocol trait live in the fedserv-api SDK crate; re-exported here so
+// the engine and the ircd modules keep referring to them as `crate::proto::*`.
 pub mod inspircd;
 
-// Normalized inbound facts, translated from the uplink's raw lines.
-#[derive(Debug, Clone)]
-pub enum NetEvent {
-    Registered,
-    EndBurst,
-    Ping { token: String, from: Option<String> },
-    Privmsg { from: String, to: String, text: String },
-    UserConnect { uid: String, nick: String, host: String },
-    NickChange { uid: String, nick: String },
-    // A channel was created or bursted (InspIRCd FJOIN). Subsequent single joins
-    // arrive as IJOIN and are not surfaced.
-    ChannelCreate { channel: String },
-    // A user joined a channel (an FJOIN member or an IJOIN), for auto-op. `op` is
-    // whether they hold channel-operator status at that point (an FJOIN prefix).
-    Join { uid: String, channel: String, op: bool },
-    // A user left a channel (PART) or was removed (KICK), for membership tracking.
-    Part { uid: String, channel: String },
-    // A user's channel-operator status changed (FMODE +o/-o), for live op tracking.
-    ChannelOp { channel: String, uid: String, op: bool },
-    // A channel's modes changed (FMODE), for enforcing mode locks. Our own
-    // changes are filtered out by the protocol layer.
-    ChannelModeChange { channel: String, modes: String },
-    // A channel's key (+k/-k) changed, tracked so GETKEY can report it.
-    ChannelKey { channel: String, key: Option<String> },
-    Quit { uid: String },
-    // An ircd relaying an IRCv3 account-registration request to us as the authority.
-    AccountRequest { reqid: String, origin: String, kind: String, account: String, p2: String, p3: String },
-    // An ircd relaying a SASL exchange step to us (the SASL agent). mode = H/S/C/D.
-    Sasl { client: String, agent: String, mode: String, data: Vec<String> },
-    Unknown { line: String },
-}
-
-// Normalized outbound intents the engine wants performed on the network.
-#[derive(Debug, Clone)]
-pub enum NetAction {
-    Burst,
-    EndBurst,
-    Pong { token: String, from: Option<String> },
-    IntroduceUser { uid: String, nick: String, ident: String, host: String, gecos: String },
-    Privmsg { from: String, to: String, text: String },
-    Notice { from: String, to: String, text: String },
-    AccountResponse { reqid: String, kind: String, account: String, status: String, code: String, message: String },
-    // A SASL exchange step back to the ircd, sourced from our SASL agent. mode = C/D.
-    Sasl { agent: String, client: String, mode: String, data: Vec<String> },
-    // Publish network state to the uplink: target "*" is server-global (e.g. the
-    // advertised SASL mechanism list), otherwise a user uid (e.g. their account).
-    Metadata { target: String, key: String, value: String },
-    // Force a user's nick (SVSNICK), e.g. renaming to a guest nick on logout.
-    // The protocol stamps the new nick's timestamp.
-    ForceNick { uid: String, nick: String },
-    // Set channel modes from services, e.g. +r on a registered channel. `from` is
-    // the pseudoclient uid to source it from (empty = the services server). The
-    // protocol stamps a timestamp the ircd will accept.
-    ChannelMode { from: String, channel: String, modes: String },
-    // Kick a user from a channel, sourced from pseudoclient `from`.
-    Kick { from: String, channel: String, uid: String, reason: String },
-    // Set a channel's topic, sourced from pseudoclient `from`.
-    Topic { from: String, channel: String, topic: String },
-    // Invite a user to a channel, sourced from pseudoclient `from`.
-    Invite { from: String, uid: String, channel: String },
-    Raw(String),
-    // Internal only, never serialized to the wire: a registration whose password
-    // still needs its (expensive) key derivation. The link layer runs the
-    // derivation off-thread, then calls Engine::complete_register.
-    DeferRegister { account: String, password: String, email: Option<String>, reply: RegReply },
-    // Internal only: a password change awaiting the same off-thread derivation.
-    // The link layer derives, then calls Engine::complete_password_change.
-    DeferPassword { account: String, password: String, agent: String, uid: String },
-    // Internal only: send an email (plaintext + optional HTML). The link layer
-    // pipes it to the configured mail command off-thread; never serialized.
-    SendEmail { to: String, subject: String, text: String, html: Option<String> },
-}
-
-// How to answer a registration once its credentials have been derived.
-#[derive(Debug, Clone)]
-pub enum RegReply {
-    // IRCv3 account-registration relay: answer the requesting ircd.
-    Relay { reqid: String, kind: String },
-    // NickServ REGISTER: NOTICE the requesting user, logging them in on success.
-    NickServ { agent: String, uid: String, nick: String },
-}
-
-pub trait Protocol: Send {
-    /// Lines to send immediately on connect (auth / capability negotiation).
-    fn handshake(&mut self) -> Vec<String>;
-    /// One raw inbound line -> zero or more normalized events.
-    fn parse(&mut self, line: &str) -> Vec<NetEvent>;
-    /// One normalized action -> the raw line(s) that realise it.
-    fn serialize(&mut self, action: &NetAction) -> Vec<String>;
-    /// Our own server id, used as the source prefix for server-sourced lines.
-    fn sid(&self) -> &str;
-}
+pub use fedserv_api::{NetAction, NetEvent, Protocol, RegReply};