Rename the project to Echo (was fedserv)

Rebrand the daemon and workspace: the binary is now `echo`, every crate
is `echo-*` (`echo-api` and the module crates), Rust imports use
`echo_*`, the gRPC proto is `proto/echo.proto` with package `echo.v1`,
and the log filter, gossip peer-name default, and on-disk store default
(`echo.db.jsonl`) follow. Docs updated throughout. No behaviour change;
crate directories and the config schema are untouched.

src/engine/db/mod.rs

@@ -39,9 +39,9 @@ pub use event::Event;
 pub(crate) use event::{apply, Scope};
 
 // Error kinds, the emailed-code purpose, and the module-facing views live in the
-// fedserv-api SDK crate; re-exported so the engine keeps naming them locally and
+// echo-api SDK crate; re-exported so the engine keeps naming them locally and
 // modules importing `crate::engine::db::{ChanError, ...}` are unaffected.
-pub use fedserv_api::{
+pub use echo_api::{
     AccountView, AjoinView, AkillView, BotView, Caps, GroupView, HelpView, IgnoreView, MemoView, NewsView, Privs, ReportView, SuspensionView, ChanAccessView, ChanAkickView, ChanError, ChanSetting, ChannelView, CertError, CodeKind, Kicker, RegError, Store, TriggerView, VhostView,
 };
 
@@ -538,7 +538,7 @@ impl ChannelInfo {
         self.access
             .iter()
             .find(|a| a.account.eq_ignore_ascii_case(account))
-            .and_then(|a| fedserv_api::level_caps(&a.level).auto)
+            .and_then(|a| echo_api::level_caps(&a.level).auto)
     }
 
     /// The matching auto-kick entry for `hostmask` (nick!user@host), if any.

src/engine/db/network.rs

@@ -376,7 +376,7 @@ impl Db {
         self.net.groups.iter().find(|g| key(&g.name) == k).map(|g| GroupView {
             name: g.name.clone(),
             founder: g.founder.clone(),
-            members: g.members.iter().map(|m| fedserv_api::GroupMemberView { account: m.account.clone(), flags: m.flags.clone() }).collect(),
+            members: g.members.iter().map(|m| echo_api::GroupMemberView { account: m.account.clone(), flags: m.flags.clone() }).collect(),
         })
     }
 
@@ -409,7 +409,7 @@ impl Db {
     pub fn channel_caps(&self, channel: &str, account: &str) -> Caps {
         let Some(c) = self.channels.get(&key(channel)) else { return Caps::default() };
         if c.founder.eq_ignore_ascii_case(account) {
-            return fedserv_api::level_caps("founder");
+            return echo_api::level_caps("founder");
         }
         let mut caps = Caps::default();
         for a in &c.access {
@@ -418,7 +418,7 @@ impl Db {
                 None => a.account.eq_ignore_ascii_case(account),
             };
             if applies {
-                caps = caps.union(fedserv_api::level_caps(&a.level));
+                caps = caps.union(echo_api::level_caps(&a.level));
             }
         }
         caps

src/engine/db/tests.rs

@@ -1,7 +1,7 @@
     use super::*;
 
     fn tmp(name: &str) -> PathBuf {
-        let p = std::env::temp_dir().join(format!("fedserv-log-{name}.jsonl"));
+        let p = std::env::temp_dir().join(format!("echo-log-{name}.jsonl"));
         let _ = std::fs::remove_file(&p);
         p
     }
@@ -12,8 +12,8 @@
 
     #[test]
     fn formats_unix_time_as_utc() {
-        assert_eq!(fedserv_api::human_time(0), "1970-01-01 00:00:00 UTC");
-        assert_eq!(fedserv_api::human_time(1783844590), "2026-07-12 08:23:10 UTC");
+        assert_eq!(echo_api::human_time(0), "1970-01-01 00:00:00 UTC");
+        assert_eq!(echo_api::human_time(1783844590), "2026-07-12 08:23:10 UTC");
     }
 
     #[test]