feat: propagate Micropub deletes to ActivityPub and Bluesky

When a post is deleted from the web backend (Micropub action=delete),
call each registered syndicator's delete() method so the post is also
removed from the Fediverse (AP Delete/Tombstone) and Bluesky
(com.atproto.repo.deleteRecord).

- patch-bluesky-syndicator-delete: adds Bluesky#deletePost(bskyUrl) to
  lib/bluesky.js and BlueskySyndicator#delete(url, syndication) to
  index.js; the bsky.app URL is resolved from the syndication array
  that postData.delete() preserves in _deletedProperties
- patch-micropub-delete-propagation: patches action.js case "delete"
  to iterate publication.syndicationTargets after postContent.delete()
  and fire syndicator.delete() fire-and-forget for any syndicator that
  exposes the method (errors logged, never break the 200 response)

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

scripts/patch-micropub-delete-propagation.mjs

@@ -0,0 +1,85 @@
+/**
+ * Patch: propagate Micropub deletes to registered syndicators.
+ *
+ * Bug:
+ *   action.js case "delete" only calls postData.delete() + postContent.delete().
+ *   It never notifies syndicators, so deleting a post from the web backend
+ *   leaves orphaned copies on ActivityPub (Fediverse) and Bluesky.
+ *
+ * Fix:
+ *   After postContent.delete() returns, iterate publication.syndicationTargets
+ *   and call syndicator.delete(url, syndication) on any syndicator that exposes
+ *   the method.  The syndication URLs are read from data._deletedProperties
+ *   (preserved by postData.delete() before stripping the properties).
+ *
+ *   Errors from individual syndicators are caught and logged — a failed remote
+ *   delete must never break the 200 response for the local delete.
+ */
+
+import { access, readFile, writeFile } from "node:fs/promises";
+
+const MARKER = "// [patch] micropub-delete-propagation";
+
+const candidates = [
+  "node_modules/@indiekit/endpoint-micropub/lib/controllers/action.js",
+];
+
+const OLD_DELETE_CASE = `      case "delete": {
+        data = await postData.delete(application, publication, url);
+        content = await postContent.delete(publication, data);
+        break;
+      }`;
+
+const NEW_DELETE_CASE = `      case "delete": { ${MARKER}
+        data = await postData.delete(application, publication, url);
+        content = await postContent.delete(publication, data);
+        // Propagate delete to syndicators (AP, Bluesky, …) ${MARKER}
+        const _deletedSyndication = data?._deletedProperties?.syndication
+          ? [data._deletedProperties.syndication].flat()
+          : [];
+        if (_deletedSyndication.length > 0 && publication.syndicationTargets?.length > 0) {
+          for (const _syndicator of publication.syndicationTargets) {
+            if (typeof _syndicator.delete === "function") {
+              _syndicator.delete(url, _deletedSyndication).catch((err) =>
+                console.warn(\`[Micropub] Syndicator delete failed (\${_syndicator.name}): \${err.message}\`),
+              );
+            }
+          }
+        }
+        break;
+      }`;
+
+async function exists(p) {
+  try { await access(p); return true; } catch { return false; }
+}
+
+let checked = 0;
+let patched = 0;
+
+for (const filePath of candidates) {
+  if (!(await exists(filePath))) continue;
+  checked++;
+
+  const source = await readFile(filePath, "utf8");
+  if (source.includes(MARKER)) {
+    console.log(`[postinstall] patch-micropub-delete-propagation: already applied to ${filePath}`);
+    continue;
+  }
+
+  if (!source.includes(OLD_DELETE_CASE)) {
+    console.warn(`[postinstall] patch-micropub-delete-propagation: snippet not found in ${filePath}`);
+    continue;
+  }
+
+  await writeFile(filePath, source.replace(OLD_DELETE_CASE, NEW_DELETE_CASE), "utf8");
+  patched++;
+  console.log(`[postinstall] Applied patch-micropub-delete-propagation to ${filePath}`);
+}
+
+if (checked === 0) {
+  console.log("[postinstall] patch-micropub-delete-propagation: no target files found");
+} else if (patched === 0) {
+  console.log("[postinstall] patch-micropub-delete-propagation: already up to date");
+} else {
+  console.log(`[postinstall] patch-micropub-delete-propagation: patched ${patched} file(s)`);
+}