fix: disable Mastodon external like/repost status posts

Serve like/repost posts as Note objects for AP content negotiation.
Returning a bare Like/Announce activity broke Mastodon's
authorize_interaction because it expects a content object (Note/Article).
Now like posts are served as ❤️ Note and reposts as 🔁 Note.

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

scripts/patch-activitypub-like-repost-content-negotiation.mjs

@@ -0,0 +1,113 @@
+import { access, readFile, writeFile } from "node:fs/promises";
+
+const patchSpecs = [
+  {
+    name: "activitypub-like-repost-content-negotiation-as-note",
+    candidates: [
+      "node_modules/@rmdes/indiekit-endpoint-activitypub/lib/jf2-to-as2.js",
+    ],
+    replacements: [
+      {
+        // Serve like/repost posts as Note objects for content negotiation.
+        // Returning a bare Like/Announce activity breaks Mastodon's
+        // authorize_interaction because it expects a content object (Note/Article).
+        oldSnippet: [
+          "  if (postType === \"like\") {",
+          "    return {",
+          "      \"@context\": \"https://www.w3.org/ns/activitystreams\",",
+          "      type: \"Like\",",
+          "      actor: actorUrl,",
+          "      object: properties[\"like-of\"],",
+          "    };",
+          "  }",
+          "",
+          "  if (postType === \"repost\") {",
+          "    return {",
+          "      \"@context\": \"https://www.w3.org/ns/activitystreams\",",
+          "      type: \"Announce\",",
+          "      actor: actorUrl,",
+          "      object: properties[\"repost-of\"],",
+          "    };",
+          "  }",
+        ].join("\n"),
+        newSnippet: [
+          "  if (postType === \"like\") {",
+          "    // Serve like posts as Note objects for AP content negotiation.",
+          "    // Returning a bare Like activity breaks Mastodon's authorize_interaction",
+          "    // flow because it expects a content object (Note/Article), not an activity.",
+          "    const likeOf = properties[\"like-of\"];",
+          "    const postUrl = resolvePostUrl(properties.url, publicationUrl);",
+          "    return {",
+          '      "@context": "https://www.w3.org/ns/activitystreams",',
+          '      type: "Note",',
+          "      id: postUrl,",
+          "      attributedTo: actorUrl,",
+          "      published: properties.published,",
+          "      url: postUrl,",
+          '      to: ["https://www.w3.org/ns/activitystreams#Public"],',
+          '      cc: [`${actorUrl.replace(/\\/$/, "")}/followers`],',
+          '      content: `\\u2764\\uFE0F <a href="${likeOf}">${likeOf}</a>`,',
+          "    };",
+          "  }",
+          "",
+          "  if (postType === \"repost\") {",
+          "    // Same rationale as like — serve as Note for content negotiation.",
+          "    const repostOf = properties[\"repost-of\"];",
+          "    const postUrl = resolvePostUrl(properties.url, publicationUrl);",
+          "    return {",
+          '      "@context": "https://www.w3.org/ns/activitystreams",',
+          '      type: "Note",',
+          "      id: postUrl,",
+          "      attributedTo: actorUrl,",
+          "      published: properties.published,",
+          "      url: postUrl,",
+          '      to: ["https://www.w3.org/ns/activitystreams#Public"],',
+          '      cc: [`${actorUrl.replace(/\\/$/, "")}/followers`],',
+          '      content: `\\u{1F501} <a href="${repostOf}">${repostOf}</a>`,',
+          "    };",
+          "  }",
+        ].join("\n"),
+      },
+    ],
+  },
+];
+
+async function applyPatch(spec) {
+  let filePath = null;
+  for (const candidate of spec.candidates) {
+    try {
+      await access(candidate);
+      filePath = candidate;
+      break;
+    } catch {
+      // try next
+    }
+  }
+
+  if (!filePath) {
+    console.warn(`[postinstall] ${spec.name}: no candidate file found, skipping`);
+    return;
+  }
+
+  let content = await readFile(filePath, "utf8");
+
+  for (const { oldSnippet, newSnippet } of spec.replacements) {
+    if (content.includes(newSnippet)) {
+      continue; // already applied
+    }
+    if (!content.includes(oldSnippet)) {
+      console.warn(`[postinstall] ${spec.name}: expected snippet not found in ${filePath}`);
+      continue;
+    }
+    content = content.replace(oldSnippet, newSnippet);
+  }
+
+  await writeFile(filePath, content, "utf8");
+  console.log(`[postinstall] ${spec.name} patch applied to ${filePath}`);
+}
+
+(async () => {
+  for (const spec of patchSpecs) {
+    await applyPatch(spec);
+  }
+})();