feat(veri): CSV dışa ve içe aktarma (harcamalar, plan kalemleri, varlık işlemleri)

- Excel uyumlu CSV indirme
- İçe aktarma: önce deneme raporu (geçerli / zaten var / satır satır hata), onayla geçerli satırlar
- Sütunlar adla, esnek tutar/tarih yazımı, ; ve , ayırıcı, Windows-1254 desteği
- Varlıkta tarih sırasına göre eldekinden fazla satış denetimi
- Ayarlar sayfasında Veri bölümü

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/src/routes/mod.rs

@@ -15,9 +15,11 @@ mod reports;
 mod review;
 mod spa;
 mod stats;
+mod transfer;
 
 use axum::{
     Router,
+    extract::DefaultBodyLimit,
     routing::{delete, get, patch, post, put},
 };
 use tower_http::{compression::CompressionLayer, trace::TraceLayer};
@@ -89,6 +91,17 @@ pub fn router(state: AppState) -> Router {
         .route("/periods/{id}/daily", get(stats::daily))
         .route("/stats/periods", get(stats::periods))
         .route("/reports/breakdown", get(reports::breakdown))
+        .route("/export/entries.csv", get(transfer::export_entries))
+        .route("/export/plan-items.csv", get(transfer::export_plan_items))
+        .route(
+            "/export/asset-transactions.csv",
+            get(transfer::export_asset_txs),
+        )
+        .route(
+            "/import/{kind}",
+            // Büyük CSV (≤ 20.000 satır) için gövde sınırı 5 MB
+            post(transfer::import).layer(DefaultBodyLimit::max(5 * 1024 * 1024)),
+        )
         .route(
             "/periods/{id}/budget",
             get(budget::get).put(budget::set_monthly),

backend/src/routes/transfer.rs

@@ -0,0 +1,149 @@
+//! CSV dışa / içe aktarma (hanenin tüm üyeleri):
+//!
+//! | Yöntem | Yol | İş |
+//! |---|---|---|
+//! | GET  | `/api/export/entries.csv?from=&to=`    | harcamalar |
+//! | GET  | `/api/export/plan-items.csv`           | plan kalemleri (tüm dönemler) |
+//! | GET  | `/api/export/asset-transactions.csv`   | varlık işlemleri |
+//! | POST | `/api/import/{tür}?commit=false\|true` | gövde: CSV metni → rapor; `commit=true` geçerli satırları yazar |
+//!
+//! `{tür}`: `entries` · `plan-items` · `asset-transactions`.
+
+use axum::{
+    Json,
+    extract::{Path, Query, State},
+    http::header,
+    response::IntoResponse,
+};
+use serde::{Deserialize, Serialize};
+use ts_rs::TS;
+
+use crate::{
+    auth::AuthUser,
+    error::{AppError, AppResult},
+    services::{
+        calendar::{format_date, today_tr},
+        transfer,
+    },
+    state::AppState,
+};
+
+fn csv_response(name: &str, body: String) -> impl IntoResponse {
+    let file = format!("kakeibo-{name}-{}.csv", format_date(today_tr()));
+    (
+        [
+            (header::CONTENT_TYPE, "text/csv; charset=utf-8".to_string()),
+            (
+                header::CONTENT_DISPOSITION,
+                format!("attachment; filename=\"{file}\""),
+            ),
+            (header::CACHE_CONTROL, "no-store".to_string()),
+        ],
+        body,
+    )
+}
+
+#[derive(Deserialize)]
+pub struct RangeQuery {
+    from: Option<String>,
+    to: Option<String>,
+}
+
+pub async fn export_entries(
+    State(s): State<AppState>,
+    auth: AuthUser,
+    Query(q): Query<RangeQuery>,
+) -> AppResult<impl IntoResponse> {
+    let body = transfer::export_entries(
+        &s.db,
+        auth.household_id,
+        q.from.as_deref().filter(|x| !x.is_empty()),
+        q.to.as_deref().filter(|x| !x.is_empty()),
+    )
+    .await?;
+    Ok(csv_response("harcamalar", body))
+}
+
+pub async fn export_plan_items(
+    State(s): State<AppState>,
+    auth: AuthUser,
+) -> AppResult<impl IntoResponse> {
+    let body = transfer::export_plan_items(&s.db, auth.household_id).await?;
+    Ok(csv_response("plan-kalemleri", body))
+}
+
+pub async fn export_asset_txs(
+    State(s): State<AppState>,
+    auth: AuthUser,
+) -> AppResult<impl IntoResponse> {
+    let body = transfer::export_asset_txs(&s.db, auth.household_id).await?;
+    Ok(csv_response("varlik-islemleri", body))
+}
+
+#[derive(Deserialize)]
+pub struct ImportQuery {
+    #[serde(default)]
+    commit: bool,
+}
+
+#[derive(Serialize, TS)]
+#[ts(export, rename = "ImportReport")]
+pub struct ReportDto {
+    /// Başlık hariç dolu satır
+    total: u32,
+    /// Eklenebilir (tekrarlar hariç); yazıldıysa yazılan
+    valid: u32,
+    /// Veritabanında zaten olduğu için atlanan
+    duplicates: u32,
+    /// Yazılan (denemede 0)
+    imported: u32,
+    errors: Vec<ImportError>,
+    /// İlk geçerli satırlar (gösterime hazır)
+    preview: Vec<Vec<String>>,
+}
+
+#[derive(Serialize, TS)]
+#[ts(export)]
+pub struct ImportError {
+    /// Dosyadaki satır numarası (başlık 1)
+    line: u32,
+    message: String,
+}
+
+pub async fn import(
+    State(s): State<AppState>,
+    auth: AuthUser,
+    Path(kind): Path<String>,
+    Query(q): Query<ImportQuery>,
+    body: String,
+) -> AppResult<Json<ReportDto>> {
+    let r = match kind.as_str() {
+        "entries" => {
+            transfer::import_entries(&s.db, auth.household_id, auth.user_id, &body, q.commit)
+                .await?
+        }
+        "plan-items" => {
+            transfer::import_plan_items(&s.db, auth.household_id, &body, q.commit).await?
+        }
+        "asset-transactions" => {
+            transfer::import_asset_txs(&s.db, auth.household_id, auth.user_id, &body, q.commit)
+                .await?
+        }
+        _ => return Err(AppError::NotFound),
+    };
+    Ok(Json(ReportDto {
+        total: r.total as u32,
+        valid: r.valid as u32,
+        duplicates: r.duplicates as u32,
+        imported: r.imported as u32,
+        errors: r
+            .errors
+            .into_iter()
+            .map(|(line, message)| ImportError {
+                line: line as u32,
+                message,
+            })
+            .collect(),
+        preview: r.preview,
+    }))
+}