Server overhaul: invite creation and CLI plumbing shared

invites::create_partner_invite is the one partner-invite path of E-12 and invite-partner; E-3's user creation moves
into invited_user; invite kinds parse through rows::token; app_version_code comes from auth. cli::render_invite
replaces the two identical render functions and cli::with_database the open/run/close block of four subcommands.
Same output, exit codes and errors.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TQd3pEP9UeN2uifbHknQ7B

server/crates/kvitt-server/src/cli/mod.rs

@@ -1,5 +1,4 @@
-//! `kvitt-server` subcommands (SPEC §10.4, exhaustive), all implemented: `serve`, `migrate` and `healthcheck` here,
-//! `bootstrap` and `pair-device` (M3), `rotate-epoch` (M4) and `invite-partner` (D-113) in their own files.
+//! `kvitt-server` subcommands (SPEC §10.4, exhaustive): `serve` and `migrate` here, the others in their own files.
 
 pub mod bootstrap;
 pub mod healthcheck;
@@ -18,7 +17,9 @@ use clap::{Parser, Subcommand};
 use tokio::net::TcpListener;
 use tokio::sync::Notify;
 
+use crate::api::invites::{self, NewInvite};
 use crate::config::Config;
+use crate::db::Db;
 use crate::error::AppError;
 use crate::{AppState, db, router, tasks};
 
@@ -79,6 +80,29 @@ pub async fn run(command: Command, config: Config) -> ExitCode {
     }
 }
 
+/// The text the invite subcommands print (AC-1.1, AC-1.6, D-113): the code in groups of four, the landing link
+/// (naming the inviting admin with `from`, D-087) and the expiry. The code goes to stdout only, never to the log
+/// (SPEC §8.7).
+pub fn render_invite(invite: &NewInvite, public_url: &str, from: Option<&str>) -> String {
+    format!(
+        "Code:    {}\nLink:    {}\nExpires: {}\n",
+        invites::display_code(&invite.code),
+        invites::invite_link(public_url, &invite.code, from),
+        invite.expires_at
+    )
+}
+
+/// Opens the database (see [`open_database`]), runs `job` on it and closes the pool again.
+pub async fn with_database<T>(
+    config: &Config,
+    job: impl AsyncFnOnce(&Db) -> Result<T, AppError>,
+) -> Result<T, AppError> {
+    let pool = open_database(config).await?;
+    let result = job(&pool).await;
+    pool.close().await;
+    result
+}
+
 /// Opens (creating if needed) the data directory and the database, and runs the migrations.
 pub async fn open_database(config: &Config) -> Result<db::Db, AppError> {
     std::fs::create_dir_all(&config.data_dir).map_err(|e| {
@@ -90,8 +114,7 @@ pub async fn open_database(config: &Config) -> Result<db::Db, AppError> {
 }
 
 async fn migrate(config: Config) -> Result<(), AppError> {
-    let pool = open_database(&config).await?;
-    pool.close().await;
+    with_database(&config, async |_| Ok(())).await?;
     tracing::info!("migrations applied");
     Ok(())
 }
@@ -100,7 +123,7 @@ async fn serve(config: Config) -> Result<(), AppError> {
     let pool = open_database(&config).await?;
     let bind = config.bind;
     // `tasks::start` installs the push queue (or logs once that push is disabled) and starts the scheduler.
-    let state = tasks::start(AppState::new(config, pool.clone())).await?;
+    let state = tasks::start(AppState::new(config, pool.clone()));
 
     let listener = TcpListener::bind(bind)
         .await