chore: satisfy clippy 1.95 (-D warnings) across the branch

- admin.rs: make the config/invite JSON response structs pub (they are
  returned from pub handlers; matches the already-pub AdminKeyView etc.)
- invite_codes/operator_settings: drop redundant reborrow (&mut *tx -> &mut tx)
- electrum: minimize a boolean (De Morgan, behavior-identical)
- relay: move the test module to end of file (items_after_test_module)

Pure lint hygiene surfaced by the current stable toolchain; no behavior
change. cargo clippy --all-targets -- -D warnings is now clean.

src/api/admin.rs

@@ -746,7 +746,7 @@ pub async fn admin_features(
 // effective config for runtime-safe edits or flags restart-required.
 
 #[derive(serde::Serialize)]
-struct AdminConfigResponse {
+pub struct AdminConfigResponse {
     /// Effective value of every editable field (all populated).
     effective: crate::config_overlay::SettingsOverlay,
     /// DB overlay (operator-set values only): a field present here has source=db;
@@ -812,7 +812,7 @@ pub struct PutConfigRequest {
 }
 
 #[derive(serde::Serialize)]
-struct PutConfigResponse {
+pub struct PutConfigResponse {
     /// "runtime" = hot-swapped, live now. "restart-required" = persisted, applies on
     /// the next (graceful) restart.
     applied: String,
@@ -954,7 +954,7 @@ pub struct MintInvitesRequest {
 }
 
 #[derive(serde::Serialize)]
-struct MintInvitesResponse {
+pub struct MintInvitesResponse {
     /// RAW single-use codes — shown ONCE (only the hash is stored, unrecoverable).
     codes: Vec<String>,
 }
@@ -984,7 +984,7 @@ pub async fn admin_invites_mint(
 }
 
 #[derive(serde::Serialize)]
-struct InviteView {
+pub struct InviteView {
     /// Non-secret: first 12 hex chars of the code hash (operator eyeball only).
     code_prefix: String,
     label: Option<String>,
@@ -994,7 +994,7 @@ struct InviteView {
 }
 
 #[derive(serde::Serialize)]
-struct InvitesListResponse {
+pub struct InvitesListResponse {
     invites: Vec<InviteView>,
     unused_count: i64,
 }

src/infra/db/invite_codes.rs

@@ -112,7 +112,7 @@ impl Database {
                 .await?;
             codes.push(code);
         }
-        self.append_admin_audit(&mut *tx, audit, secret).await?;
+        self.append_admin_audit(&mut tx, audit, secret).await?;
         tx.commit().await?;
         Ok(codes)
     }

src/infra/db/operator_settings.rs

@@ -148,7 +148,7 @@ impl Database {
         .execute(&mut *tx)
         .await?;
 
-        self.append_admin_audit(&mut *tx, audit, secret).await?;
+        self.append_admin_audit(&mut tx, audit, secret).await?;
         tx.commit().await?;
         Ok(version)
     }

src/infra/electrum.rs

@@ -489,7 +489,7 @@ impl ElectrumClient {
         let use_primary = self
             .primary
             .as_ref()
-            .filter(|_| !(self.primary_in_cooldown(now) && !self.fallbacks.is_empty()));
+            .filter(|_| !self.primary_in_cooldown(now) || self.fallbacks.is_empty());
 
         let mut last_err = AppError::NodeError("all Electrum servers failed".into());
 

src/infra/relay/mod.rs

@@ -145,6 +145,27 @@ struct NostrRelayProvider {
     write_allowlist: HashSet<String>,
 }
 
+impl RelayProvider for NostrRelayProvider {
+    fn kind(&self) -> &'static str {
+        self.kind
+    }
+    fn advertised_url(&self) -> &str {
+        &self.advertised_url
+    }
+    fn write_policy(&self) -> WritePolicy {
+        self.policy
+    }
+    fn inbound_pow_bits(&self) -> u8 {
+        self.inbound_pow_bits
+    }
+    fn max_event_bytes(&self) -> usize {
+        self.max_event_bytes
+    }
+    fn is_write_allowlisted(&self, author_hex: &str) -> bool {
+        !self.write_allowlist.is_empty() && self.write_allowlist.contains(author_hex)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::allowlist_entry_to_hex;
@@ -175,24 +196,3 @@ mod tests {
         assert_eq!(allowlist_entry_to_hex("deadbeef"), None); // too short
     }
 }
-
-impl RelayProvider for NostrRelayProvider {
-    fn kind(&self) -> &'static str {
-        self.kind
-    }
-    fn advertised_url(&self) -> &str {
-        &self.advertised_url
-    }
-    fn write_policy(&self) -> WritePolicy {
-        self.policy
-    }
-    fn inbound_pow_bits(&self) -> u8 {
-        self.inbound_pow_bits
-    }
-    fn max_event_bytes(&self) -> usize {
-        self.max_event_bytes
-    }
-    fn is_write_allowlisted(&self, author_hex: &str) -> bool {
-        !self.write_allowlist.is_empty() && self.write_allowlist.contains(author_hex)
-    }
-}