refactor(domain): introduce the Feed aggregate as the write-path API

Add a Feed aggregate class owning config + the email index, with create,
ingest, removeEmails, isExpired and accepts delegating to the existing
pure invariant functions. FeedRepository gains load/save/saveMetadata
that reconstitute and persist the aggregate.

All write paths now go through it: createFeedRecord (Feed.create),
email ingestion (feed.ingest), and every email deletion in the admin UI
and REST API (feed.removeEmails) — no route mutates metadata.emails
directly anymore. KV key strings unchanged.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/routes/admin.test.ts

@@ -815,6 +815,10 @@ describe("Admin Routes", () => {
           "feeds:list",
           JSON.stringify({ feeds: [{ id: feedId, title: "F" }] }),
         );
+        await r2Env.EMAIL_STORAGE.put(
+          `feed:${feedId}:config`,
+          JSON.stringify({ title: "F", language: "en", created_at: 1 }),
+        );
         const emailKey = `feed:${feedId}:1`;
         await r2Env.EMAIL_STORAGE.put(
           emailKey,

src/routes/admin/emails.tsx

@@ -650,18 +650,13 @@ emailsRouter.post("/emails/:emailKey/delete", async (c) => {
       return c.text("Feed ID is required", 400);
     }
 
-    const feedMetadata = await repo.getMetadata(feedId);
+    const feed = await repo.load(feedId);
 
     await repo.deleteEmail(emailKey);
-    await deleteAttachmentsForEmails(env, feedMetadata?.emails ?? [], [
-      emailKey,
-    ]);
-
-    if (feedMetadata) {
-      feedMetadata.emails = feedMetadata.emails.filter(
-        (email) => email.key !== emailKey,
-      );
-      await repo.putMetadata(feedId, feedMetadata);
+    if (feed) {
+      const { removed } = feed.removeEmails([emailKey]);
+      await deleteAttachmentsForEmails(env, removed, [emailKey]);
+      await repo.saveMetadata(feed);
     }
 
     if (wantsJson) return c.json({ ok: true, emailKey, feedId });
@@ -690,15 +685,15 @@ emailsRouter.post("/feeds/:feedId/emails/bulk-delete", async (c) => {
     (c.req.header("Accept") || "").includes("application/json");
 
   try {
-    const feedMetadata = await repo.getMetadata(feedId);
+    const feed = await repo.load(feedId);
 
-    if (!feedMetadata) {
+    if (!feed) {
       return wantsJson
         ? c.json({ ok: false, error: "Feed not found" }, 404)
         : c.text("Feed not found", 404);
     }
 
-    const allowedKeys = new Set(feedMetadata.emails.map((email) => email.key));
+    const allowedKeys = new Set(feed.metadata.emails.map((email) => email.key));
 
     if (wantsJson) {
       const body = (await c.req.json().catch(() => null)) as {
@@ -728,13 +723,10 @@ emailsRouter.post("/feeds/:feedId/emails/bulk-delete", async (c) => {
 
       const { ok: deletedOk, failed: failedEmailKeys } =
         await deleteKeysWithConcurrency(emailStorage, candidates, 35);
-      await deleteAttachmentsForEmails(env, feedMetadata.emails, candidates);
+      await deleteAttachmentsForEmails(env, feed.metadata.emails, candidates);
 
-      const deletedSet = new Set(deletedOk);
-      feedMetadata.emails = feedMetadata.emails.filter(
-        (email) => !deletedSet.has(email.key),
-      );
-      await repo.putMetadata(feedId, feedMetadata);
+      feed.removeEmails(deletedOk);
+      await repo.saveMetadata(feed);
 
       return c.json({
         ok: failedEmailKeys.length === 0,
@@ -759,13 +751,10 @@ emailsRouter.post("/feeds/:feedId/emails/bulk-delete", async (c) => {
       candidates,
       35,
     );
-    await deleteAttachmentsForEmails(env, feedMetadata.emails, candidates);
+    await deleteAttachmentsForEmails(env, feed.metadata.emails, candidates);
 
-    const deletedSet = new Set(deletedOk);
-    feedMetadata.emails = feedMetadata.emails.filter(
-      (email) => !deletedSet.has(email.key),
-    );
-    await repo.putMetadata(feedId, feedMetadata);
+    feed.removeEmails(deletedOk);
+    await repo.saveMetadata(feed);
 
     return c.redirect(
       `/admin/feeds/${feedId}/emails?message=bulkDeleted&count=${deletedOk.length}`,

src/routes/api/index.ts

@@ -345,15 +345,16 @@ apiApp.openapi(
     const repo = FeedRepository.from(env);
     const { feedId, entryId } = c.req.valid("param");
     const receivedAt = parseInt(entryId, 10);
-    const metadata = await repo.getMetadata(feedId);
-    const metaEntry = metadata?.emails.find((e) => e.receivedAt === receivedAt);
-    if (!metadata || !metaEntry)
-      return c.json({ error: "Email not found" }, 404);
+    const feed = await repo.load(feedId);
+    const metaEntry = feed?.metadata.emails.find(
+      (e) => e.receivedAt === receivedAt,
+    );
+    if (!feed || !metaEntry) return c.json({ error: "Email not found" }, 404);
 
     await repo.deleteEmail(metaEntry.key);
-    await deleteAttachmentsForEmails(env, metadata.emails, [metaEntry.key]);
-    metadata.emails = metadata.emails.filter((e) => e.key !== metaEntry.key);
-    await repo.putMetadata(feedId, metadata);
+    const { removed } = feed.removeEmails([metaEntry.key]);
+    await deleteAttachmentsForEmails(env, removed, [metaEntry.key]);
+    await repo.saveMetadata(feed);
 
     return c.json({ ok: true }, 200);
   },