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.

modules/reportserv/src/close.rs

@@ -1,4 +1,4 @@
-use fedserv_api::{Sender, ServiceCtx, Store};
+use echo_api::{Sender, ServiceCtx, Store};
 
 // CLOSE <id> (aka RESOLVE): mark a report resolved.
 pub fn handle(me: &str, from: &Sender, id: Option<&str>, ctx: &mut ServiceCtx, db: &mut dyn Store) {

modules/reportserv/src/del.rs

@@ -1,4 +1,4 @@
-use fedserv_api::{Sender, ServiceCtx, Store};
+use echo_api::{Sender, ServiceCtx, Store};
 
 // DEL <id> (aka REMOVE): delete a report outright.
 pub fn handle(me: &str, from: &Sender, id: Option<&str>, ctx: &mut ServiceCtx, db: &mut dyn Store) {

modules/reportserv/src/lib.rs

@@ -8,7 +8,7 @@
 //! `lib.rs` holds the dispatcher and the shared oper guard; each command lives
 //! in its own file.
 
-use fedserv_api::{NetView, Sender, Service, ServiceCtx, Store};
+use echo_api::{NetView, Sender, Service, ServiceCtx, Store};
 
 #[path = "report.rs"]
 mod report;

modules/reportserv/src/list.rs

@@ -1,4 +1,4 @@
-use fedserv_api::{Sender, ServiceCtx, Store};
+use echo_api::{Sender, ServiceCtx, Store};
 
 // LIST [ALL]: operators list the open reports (or every report with ALL).
 pub fn handle(me: &str, from: &Sender, arg: Option<&str>, ctx: &mut ServiceCtx, db: &mut dyn Store) {

modules/reportserv/src/report.rs

@@ -1,4 +1,4 @@
-use fedserv_api::{Sender, ServiceCtx, Store};
+use echo_api::{Sender, ServiceCtx, Store};
 
 // REPORT <nick|#channel> <reason>: file an abuse report. Rate-limited.
 pub fn handle(me: &str, from: &Sender, rest: &[&str], ctx: &mut ServiceCtx, db: &mut dyn Store) {

modules/reportserv/src/view.rs

@@ -1,4 +1,4 @@
-use fedserv_api::{human_time, Sender, ServiceCtx, Store};
+use echo_api::{human_time, Sender, ServiceCtx, Store};
 
 // VIEW <id> (aka READ): operators read a report in full.
 pub fn handle(me: &str, from: &Sender, id: Option<&str>, ctx: &mut ServiceCtx, db: &mut dyn Store) {