feat: API endpoints for article history listing and provenance

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/handlers/article_history.rs

@@ -0,0 +1,78 @@
+//! Handlers for article history and provenance endpoints.
+
+use axum::extract::{Path, Query, State};
+use axum::response::IntoResponse;
+use axum::Json;
+use serde::Deserialize;
+use uuid::Uuid;
+
+use crate::app_state::AppState;
+use crate::db;
+use crate::errors::AppError;
+use crate::middleware::auth::AuthUser;
+
+#[derive(Deserialize)]
+pub struct HistoryQuery {
+    pub limit: Option<i64>,
+    pub offset: Option<i64>,
+    pub status: Option<String>,
+    pub source_type: Option<String>,
+}
+
+/// GET /api/v1/article-history
+///
+/// Returns paginated article history with optional filters.
+pub async fn list_history(
+    auth_user: AuthUser,
+    State(state): State<AppState>,
+    Query(params): Query<HistoryQuery>,
+) -> Result<impl IntoResponse, AppError> {
+    let limit = params.limit.unwrap_or(50).clamp(1, 200);
+    let offset = params.offset.unwrap_or(0).max(0);
+
+    let items = db::article_history::list_history(
+        &state.pool,
+        auth_user.id,
+        limit,
+        offset,
+        params.status.as_deref(),
+        params.source_type.as_deref(),
+    )
+    .await?;
+
+    let total = db::article_history::count_history(
+        &state.pool,
+        auth_user.id,
+        params.status.as_deref(),
+        params.source_type.as_deref(),
+    )
+    .await?;
+
+    Ok(Json(serde_json::json!({
+        "items": items,
+        "total": total
+    })))
+}
+
+/// GET /api/v1/syntheses/:id/provenance
+///
+/// Returns all article history entries for the generation run
+/// that produced the given synthesis.
+pub async fn get_provenance(
+    auth_user: AuthUser,
+    State(state): State<AppState>,
+    Path(synthesis_id): Path<Uuid>,
+) -> Result<impl IntoResponse, AppError> {
+    // Verify the synthesis belongs to this user and get its job_id
+    let synthesis = db::syntheses::get_by_id_for_user(&state.pool, synthesis_id, auth_user.id)
+        .await?
+        .ok_or_else(|| AppError::NotFound("Synthesis not found".into()))?;
+
+    let job_id = synthesis.job_id.ok_or_else(|| {
+        AppError::NotFound("No tracing data available for this synthesis".into())
+    })?;
+
+    let items = db::article_history::list_by_job_id(&state.pool, auth_user.id, job_id).await?;
+
+    Ok(Json(items))
+}

backend/src/handlers/mod.rs

@@ -1,3 +1,4 @@
+pub mod article_history;
 pub mod admin;
 pub mod api_keys;
 pub mod auth;

backend/src/router.rs

@@ -54,6 +54,9 @@ pub fn build_router(state: AppState, config: &AppConfig) -> Router {
         // to avoid ambiguity with path parameter matching
         .route("/syntheses/generate", post(handlers::generation::trigger_generate))
         .route("/syntheses/generate/{job_id}/progress", get(handlers::generation::progress_stream))
+        // Article history & provenance routes (authenticated)
+        .route("/article-history", get(handlers::article_history::list_history))
+        .route("/syntheses/{id}/provenance", get(handlers::article_history::get_provenance))
         // Syntheses CRUD routes (authenticated)
         .route("/syntheses", get(handlers::syntheses::list))
         .route("/syntheses/{id}", get(handlers::syntheses::get))