modules: split services and the ircd link into external crates

nickserv, chanserv and the InspIRCd protocol move out of the binary into their
own workspace crates (fedserv-nickserv, fedserv-chanserv, fedserv-inspircd),
each depending only on fedserv-api. human_time and the branded account emails
move into the SDK crate so a module needs nothing from core; the engine keeps
its own inherent methods and builds emails via fedserv-api too. The bin now
constructs each module from its crate instead of an in-tree #[path] include.
Proves the SDK is self-sufficient: a third-party module is the same shape.

chanserv/src/status.rs

@@ -0,0 +1,29 @@
+use fedserv_api::Store;
+use fedserv_api::{Sender, ServiceCtx};
+use fedserv_api::NetView;
+
+// STATUS <#channel> [nick]: show a user's access level (self if no nick).
+pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, net: &dyn NetView, db: &dyn Store) {
+    let Some(&chan) = args.get(1) else {
+        ctx.notice(me, from.uid, "Syntax: STATUS <#channel> [nick]");
+        return;
+    };
+    let Some(info) = db.channel(chan) else {
+        ctx.notice(me, from.uid, format!("\x02{chan}\x02 isn't registered."));
+        return;
+    };
+    let (label, account) = match args.get(2) {
+        Some(&nick) => (nick.to_string(), net.uid_by_nick(nick).and_then(|u| net.account_of(u)).map(str::to_string)),
+        None => (from.nick.to_string(), from.account.map(str::to_string)),
+    };
+    let level = match account.as_deref() {
+        None => "none (not logged in)",
+        Some(a) if info.founder.eq_ignore_ascii_case(a) => "founder",
+        Some(a) => match info.join_mode(a) {
+            Some("+o") => "op",
+            Some("+v") => "voice",
+            _ => "none",
+        },
+    };
+    ctx.notice(me, from.uid, format!("\x02{label}\x02 access on \x02{chan}\x02: \x02{level}\x02"));
+}