clean(presentation): strip comments, kill dead code, extract constants

- remove all doc/inline comments
- delete unused ApiError variants (AuthRequired, NotImplemented) and helpers (internal, not_implemented)
- prefix lifetime-only AppState fields with _ to suppress dead_code warning
- extract magic numbers: TICK_INTERVAL_SECS, EXPIRY_THRESHOLD_HOURS, POLL_INTERVAL_SECS, EVENT_BUS_CAPACITY, DEFAULT_ACTIVITY_LIMIT, DEFAULT_SEARCH_LIMIT, etc
- replace inline serde_json::json! in sync_status with typed SyncStatusEntry
- fix mid-file import in schedule handler
- fix extractors: strip_prefix instead of magic offset 6
- fix unreachable pattern in wire_repositories with cfg guard
- use eq_ignore_ascii_case for content-type header check

crates/presentation/src/handlers/auth.rs

@@ -1,5 +1,3 @@
-//! Authentication handlers.
-
 use axum::Json;
 use axum::extract::State;
 
@@ -10,7 +8,9 @@ use crate::errors::ApiError;
 use crate::extractors::CurrentUser;
 use crate::state::AppState;
 
-/// POST /auth/register
+const TOKEN_TYPE_BEARER: &str = "Bearer";
+const SECS_PER_HOUR: u64 = 3600;
+
 pub async fn register(
     State(state): State<AppState>,
     Json(req): Json<RegisterRequest>,
@@ -23,7 +23,6 @@ pub async fn register(
     Ok(Json(UserResponse::from(user)))
 }
 
-/// POST /auth/login
 pub async fn login(
     State(state): State<AppState>,
     Json(req): Json<LoginRequest>,
@@ -36,25 +35,22 @@ pub async fn login(
     let (access_token, refresh_token) = create_tokens(&user, &state, req.remember_me)?;
     Ok(Json(TokenResponse {
         access_token,
-        token_type: "Bearer".to_string(),
-        expires_in: state.config.jwt_expiry_hours * 3600,
+        token_type: TOKEN_TYPE_BEARER.to_string(),
+        expires_in: state.config.jwt_expiry_hours * SECS_PER_HOUR,
         refresh_token,
     }))
 }
 
-/// POST /auth/logout — no-op for JWT (stateless)
 pub async fn logout() -> Result<Json<serde_json::Value>, ApiError> {
     Ok(Json(serde_json::json!({"message": "logged out"})))
 }
 
-/// GET /auth/me
 pub async fn me(
     CurrentUser(user): CurrentUser,
 ) -> Result<Json<UserResponse>, ApiError> {
     Ok(Json(UserResponse::from(user)))
 }
 
-/// POST /auth/token — exchange credentials for tokens
 #[cfg(feature = "auth-jwt")]
 pub async fn get_token(
     State(state): State<AppState>,
@@ -68,13 +64,12 @@ pub async fn get_token(
     let (access_token, refresh_token) = create_tokens(&user, &state, req.remember_me)?;
     Ok(Json(TokenResponse {
         access_token,
-        token_type: "Bearer".to_string(),
-        expires_in: state.config.jwt_expiry_hours * 3600,
+        token_type: TOKEN_TYPE_BEARER.to_string(),
+        expires_in: state.config.jwt_expiry_hours * SECS_PER_HOUR,
         refresh_token,
     }))
 }
 
-/// POST /auth/refresh — refresh an access token
 #[cfg(feature = "auth-jwt")]
 pub async fn refresh_token(
     State(state): State<AppState>,
@@ -106,8 +101,8 @@ pub async fn refresh_token(
     let (access_token, refresh_token) = create_tokens(&user, &state, true)?;
     Ok(Json(TokenResponse {
         access_token,
-        token_type: "Bearer".to_string(),
-        expires_in: state.config.jwt_expiry_hours * 3600,
+        token_type: TOKEN_TYPE_BEARER.to_string(),
+        expires_in: state.config.jwt_expiry_hours * SECS_PER_HOUR,
         refresh_token,
     }))
 }