style(server): cargo fmt + clippy fixes for v2 keystone (CI green)

The Task 2/3/authz commits failed CI at the first gate (cargo fmt --all
--check), which short-circuited before clippy/build/test ran. Verified on the
build host (172.16.3.30): the v2 server compiles and all 18 tests pass; only
3 cosmetic issues blocked CI, all fixed here:
- cargo fmt --all (whitespace, 3 files)
- clippy unused_imports: drop ViewerClaims from auth/mod.rs re-export
- clippy doc_overindented_list_items: de-indent one doc line in sessions.rs
Testing Agent confirmed fmt + clippy -D warnings + build --release + test are
all green with these applied. No logic changes.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server/src/api/sessions.rs

@@ -95,8 +95,13 @@ pub async fn mint_viewer_token(
     State(state): State<AppState>,
     Path(id): Path<String>,
 ) -> ApiResult<Json<ViewerTokenResponse>> {
-    let session_id = Uuid::parse_str(&id)
+    let session_id = Uuid::parse_str(&id).map_err(|_| {
-        .map_err(|_| err(StatusCode::BAD_REQUEST, "INVALID_SESSION_ID", "Invalid session ID"))?;
+        err(
+            StatusCode::BAD_REQUEST,
+            "INVALID_SESSION_ID",
+            "Invalid session ID",
+        )
+    })?;
 
     // TIERED AUTHORIZATION GATE (closes audit CRITICAL #1 — authz-strength split).
     // Authentication alone is not enough, and a single `view` check is too coarse
@@ -127,7 +132,11 @@ pub async fn mint_viewer_token(
 
     // The session must exist (live session manager is the
     // source of truth for joinable sessions, matching GET /api/sessions/:id).
-    let session = state.sessions.get_session(session_id).await.ok_or_else(|| {
+    let session = state
+        .sessions
+        .get_session(session_id)
+        .await
+        .ok_or_else(|| {
             err(
                 StatusCode::NOT_FOUND,
                 "SESSION_NOT_FOUND",

server/src/auth/agent_keys.rs

@@ -111,7 +111,10 @@ mod tests {
         let key = generate_agent_key();
         assert!(key.starts_with(AGENT_KEY_PREFIX));
         // prefix + 32 bytes * 2 hex chars
-        assert_eq!(key.len(), AGENT_KEY_PREFIX.len() + AGENT_KEY_RANDOM_BYTES * 2);
+        assert_eq!(
+            key.len(),
+            AGENT_KEY_PREFIX.len() + AGENT_KEY_RANDOM_BYTES * 2
+        );
     }
 
     #[test]

server/src/auth/mod.rs

@@ -8,7 +8,7 @@ pub mod jwt;
 pub mod password;
 pub mod token_blacklist;
 
-pub use jwt::{Claims, JwtConfig, ViewerAccess, ViewerClaims};
+pub use jwt::{Claims, JwtConfig, ViewerAccess};
 pub use password::{generate_random_password, hash_password, verify_password};
 pub use token_blacklist::TokenBlacklist;
 

server/src/relay/mod.rs

@@ -338,13 +338,15 @@ async fn validate_agent_api_key(state: &AppState, api_key: &str) -> AgentKeyAuth
             crate::auth::agent_keys::verify_agent_key(db.pool(), api_key).await
         {
             // Resolve the trusted identity from the authenticated key's machine.
-            let trusted_agent_id = match db::machines::get_machine_by_id(db.pool(), machine_id)
+            let trusted_agent_id =
-                .await
+                match db::machines::get_machine_by_id(db.pool(), machine_id).await {
-            {
                     Ok(Some(machine)) => Some(machine.agent_id),
                     Ok(None) => None,
                     Err(e) => {
-                    tracing::error!("Failed to resolve machine for authenticated agent key: {}", e);
+                        tracing::error!(
+                            "Failed to resolve machine for authenticated agent key: {}",
+                            e
+                        );
                         None
                     }
                 };
@@ -403,7 +405,10 @@ pub async fn viewer_ws_handler(
     // 1. Signature + expiry + `purpose == "viewer"`. A login JWT fails this
     //    (wrong claim shape / no `purpose`), so login tokens are no longer
     //    accepted on the viewer plane.
-    let claims = state.jwt_config.validate_viewer_token(&token).map_err(|e| {
+    let claims = state
+        .jwt_config
+        .validate_viewer_token(&token)
+        .map_err(|e| {
             warn!(
                 "Viewer connection rejected from {}: invalid viewer token: {}",
                 client_ip, e