feat(admin): observability — job history, live now-analyzing, durations & metrics (0.84.0) (#6)

backend/src/domain/crawl_metrics.rs

@@ -0,0 +1,43 @@
+//! Timing metrics for crawler operations (see `crawl_metrics` table, 0028).
+//!
+//! One [`OpRow`] per completed operation (manga list walk, manga detail,
+//! cover, whole chapter); [`OpSummary`] is the per-type average roll-up that
+//! drives the admin Metrics tab. Per-page crawl timing is derived on the
+//! client from the `chapter` summary's `avg_items` (pages/chapter), not
+//! stored per image. Analysis duration lives on `page_analysis`, not here.
+
+use chrono::{DateTime, Utc};
+use serde::Serialize;
+use sqlx::FromRow;
+use uuid::Uuid;
+
+/// Per-operation-type average roll-up over a time window.
+#[derive(Debug, Clone, Serialize, FromRow)]
+pub struct OpSummary {
+    /// `manga_list` | `manga_detail` | `manga_cover` | `chapter`.
+    pub op: String,
+    /// Mean duration in milliseconds (`NULL`→absent only when `n = 0`).
+    pub avg_ms: Option<f64>,
+    /// Total operations in the window.
+    pub n: i64,
+    pub ok: i64,
+    pub failed: i64,
+    /// Mean `items` (pages/chapter, mangas/list-walk); `None` when unused.
+    pub avg_items: Option<f64>,
+}
+
+/// One timed operation, resolved to manga/chapter labels for the recent-ops log.
+#[derive(Debug, Clone, Serialize, FromRow)]
+pub struct OpRow {
+    pub id: Uuid,
+    pub op: String,
+    pub manga_id: Option<Uuid>,
+    pub manga_title: Option<String>,
+    pub chapter_id: Option<Uuid>,
+    pub chapter_number: Option<i32>,
+    pub outcome: String,
+    pub duration_ms: i64,
+    pub items: Option<i32>,
+    pub error: Option<String>,
+    pub finished_at: DateTime<Utc>,
+}