Server: no built-in public host, no trusted proxy by default; OpenAPI server variable host (D-123)

KVITT_PUBLIC_URL is required: every command refuses to start without it (compose
always sets it). KVITT_TRUSTED_PROXY defaults to none, which the rate limiter never
resolves. contracts/openapi.yaml and the utoipa document: servers[].url
https://{host}:8443 with variable host (default kvitt.example.invalid). E-7 and E-12
examples on kvitt.example.invalid.

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

server/crates/kvitt-server/tests/skeleton/support.rs

@@ -47,8 +47,10 @@ impl TestApp {
 
     async fn migrated_to(target: Option<i64>) -> Self {
         let dir = TempDir::new();
-        let config = Config::from_lookup(|k| {
-            (k == "KVITT_DATA_DIR").then(|| dir.0.to_string_lossy().into_owned())
+        let config = Config::from_lookup(|k| match k {
+            "KVITT_DATA_DIR" => Some(dir.0.to_string_lossy().into_owned()),
+            "KVITT_PUBLIC_URL" => Some("https://kvitt.example.invalid:8443".to_owned()),
+            _ => None,
         })
         .unwrap();
         let pool = db::connect(&config.database_path()).await.unwrap();