Phase 1: storage + catalog layer

- storaged: object_store backend (LocalFileSystem), PUT/GET/DELETE/LIST endpoints
- shared: arrow_helpers with Parquet roundtrip + schema fingerprinting (2 tests)
- catalogd: in-memory registry with write-ahead manifest persistence to object storage
- catalogd: POST/GET /datasets, GET /datasets/by-name/{name}
- gateway: wires storaged + catalogd with shared object_store state
- Phase tracker updated: Phase 0 + Phase 1 gates passed

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/catalogd/src/service.rs

@@ -1,9 +1,125 @@
-use axum::{Router, routing::get};
+use axum::{
+    Json, Router,
+    extract::{Path, State},
+    http::StatusCode,
+    response::IntoResponse,
+    routing::{get, post},
+};
+use serde::{Deserialize, Serialize};
+use shared::types::{DatasetId, ObjectRef, SchemaFingerprint};
+use uuid::Uuid;
 
-pub fn router() -> Router {
-    Router::new().route("/health", get(health))
+use crate::registry::Registry;
+
+pub fn router(registry: Registry) -> Router {
+    Router::new()
+        .route("/health", get(health))
+        .route("/datasets", post(create_dataset))
+        .route("/datasets", get(list_datasets))
+        .route("/datasets/{id}", get(get_dataset))
+        .route("/datasets/by-name/{name}", get(get_dataset_by_name))
+        .with_state(registry)
 }
 
 async fn health() -> &'static str {
     "catalogd ok"
 }
+
+#[derive(Deserialize)]
+struct CreateDatasetRequest {
+    name: String,
+    schema_fingerprint: String,
+    objects: Vec<ObjectRefRequest>,
+}
+
+#[derive(Deserialize)]
+struct ObjectRefRequest {
+    bucket: String,
+    key: String,
+    size_bytes: u64,
+}
+
+#[derive(Serialize)]
+struct DatasetResponse {
+    id: String,
+    name: String,
+    schema_fingerprint: String,
+    objects: Vec<ObjectRefResponse>,
+    created_at: String,
+    updated_at: String,
+}
+
+#[derive(Serialize)]
+struct ObjectRefResponse {
+    bucket: String,
+    key: String,
+    size_bytes: u64,
+    created_at: String,
+}
+
+impl From<&shared::types::DatasetManifest> for DatasetResponse {
+    fn from(m: &shared::types::DatasetManifest) -> Self {
+        Self {
+            id: m.id.to_string(),
+            name: m.name.clone(),
+            schema_fingerprint: m.schema_fingerprint.0.clone(),
+            objects: m.objects.iter().map(|o| ObjectRefResponse {
+                bucket: o.bucket.clone(),
+                key: o.key.clone(),
+                size_bytes: o.size_bytes,
+                created_at: o.created_at.to_rfc3339(),
+            }).collect(),
+            created_at: m.created_at.to_rfc3339(),
+            updated_at: m.updated_at.to_rfc3339(),
+        }
+    }
+}
+
+async fn create_dataset(
+    State(registry): State<Registry>,
+    Json(req): Json<CreateDatasetRequest>,
+) -> impl IntoResponse {
+    let now = chrono::Utc::now();
+    let objects: Vec<ObjectRef> = req.objects.into_iter().map(|o| ObjectRef {
+        bucket: o.bucket,
+        key: o.key,
+        size_bytes: o.size_bytes,
+        created_at: now,
+    }).collect();
+
+    match registry.register(req.name, SchemaFingerprint(req.schema_fingerprint), objects).await {
+        Ok(manifest) => {
+            let resp = DatasetResponse::from(&manifest);
+            Ok((StatusCode::CREATED, Json(resp)))
+        }
+        Err(e) => Err((StatusCode::INTERNAL_SERVER_ERROR, e)),
+    }
+}
+
+async fn list_datasets(State(registry): State<Registry>) -> impl IntoResponse {
+    let datasets = registry.list().await;
+    let resp: Vec<DatasetResponse> = datasets.iter().map(DatasetResponse::from).collect();
+    Json(resp)
+}
+
+async fn get_dataset(
+    State(registry): State<Registry>,
+    Path(id): Path<String>,
+) -> impl IntoResponse {
+    let uuid = Uuid::parse_str(&id).map_err(|e| (StatusCode::BAD_REQUEST, e.to_string()))?;
+    let dataset_id = DatasetId(uuid);
+    match registry.get(&dataset_id).await {
+        Some(manifest) => Ok(Json(DatasetResponse::from(&manifest))),
+        None => Err((StatusCode::NOT_FOUND, format!("dataset not found: {id}"))),
+    }
+}
+
+async fn get_dataset_by_name(
+    State(registry): State<Registry>,
+    Path(name): Path<String>,
+) -> impl IntoResponse {
+    match registry.get_by_name(&name).await {
+        Some(manifest) => Ok(Json(DatasetResponse::from(&manifest))),
+        None => Err((StatusCode::NOT_FOUND, format!("dataset not found: {name}"))),
+    }
+}