diff --git a/.github/workflows/app-submission.yml b/.github/workflows/app-submission.yml
index 745a9b4..af7e78f 100644
--- a/.github/workflows/app-submission.yml
+++ b/.github/workflows/app-submission.yml
@@ -56,6 +56,8 @@ jobs:
             // Mirrors scripts/build-catalog.mjs — keep in lockstep.
             const APP_TYPES = ['mobile', 'web', 'desktop', 'terminal', 'bot', 'integration'];
             const APP_IMAGE_HOSTS = ['raw.githubusercontent.com', 'user-images.githubusercontent.com', 'github.com'];
+            const MAX_PLATFORM_LEN = 32;
+            const MAX_PLATFORMS = 6;
 
             // --- 1. Parse the issue-form body into a { heading: value } map ---
             // GitHub renders each form field as "### <label>\n\n<value>", with
@@ -98,8 +100,17 @@ jobs:
               try { const u = new URL(v); return u.protocol === 'http:' || u.protocol === 'https:'; }
               catch { return false; }
             };
+            // github.com/<owner>/<repo>/blob/<ref>/<path> serves an HTML page, not
+            // the image — it passes the host allowlist but renders as a broken
+            // image on the site. Rewrite it to the raw host rather than bouncing
+            // the submission, since it's the link GitHub's UI hands people.
+            const rawify = (v) => {
+              const m = v.match(/^https:\/\/github\.com\/([^/]+)\/([^/]+)\/blob\/(.+)$/);
+              return m ? `https://raw.githubusercontent.com/${m[1]}/${m[2]}/${m[3]}` : v;
+            };
             const checkImage = (v, field) => {
               if (!v) return '';
+              v = rawify(v);
               let u;
               try { u = new URL(v); }
               catch { problems.push(`**${field}** is not a valid URL.`); return ''; }
@@ -125,6 +136,17 @@ jobs:
               problems.push(`**Description** must be 280 characters or fewer (yours is ${description.length}).`);
             const iconUrl = checkImage(icon, 'Icon URL');
             const shotUrl = checkImage(screenshot, 'Screenshot URL');
+            // Truncating a platform to fit would mangle it ("Progressive Web-App
+            // (PWA)" -> "...(PWA"), so say so instead and let the submitter edit.
+            const platforms = platformsRaw
+              .split(',').map((p) => p.trim()).filter(Boolean).slice(0, MAX_PLATFORMS);
+            for (const p of platforms) {
+              if (p.length > MAX_PLATFORM_LEN)
+                problems.push(
+                  `**Platforms** entry \`${p}\` must be ${MAX_PLATFORM_LEN} characters or fewer ` +
+                  `(it is ${p.length}).`,
+                );
+            }
 
             const fail = async (lines) => {
               await github.rest.issues.createComment({
@@ -146,10 +168,6 @@ jobs:
               .replace(/^-+|-+$/g, '')
               .slice(0, 48) || `app-${issue.number}`;
 
-            const platforms = platformsRaw
-              .split(',').map((p) => p.trim()).filter(Boolean)
-              .map((p) => p.slice(0, 24)).slice(0, 6);
-
             const app = { name, url, type };
             if (description) app.description = description;
             if (author) app.author = author.slice(0, 60);
diff --git a/scripts/build-catalog.mjs b/scripts/build-catalog.mjs
index f53aa4b..f7ccd26 100644
--- a/scripts/build-catalog.mjs
+++ b/scripts/build-catalog.mjs
@@ -51,6 +51,8 @@ const APP_TYPES = ['mobile', 'web', 'desktop', 'terminal', 'bot', 'skin', 'integ
 // web/lib/apps.ts — the web tier renders these through next/image, which refuses
 // any host not in remotePatterns.
 const APP_IMAGE_HOSTS = ['raw.githubusercontent.com', 'user-images.githubusercontent.com', 'github.com'];
+const MAX_PLATFORM_LEN = 32;
+const MAX_PLATFORMS = 6;
 
 const errors = [];
 const fail = (where, msg) => errors.push(`${where}: ${msg}`);
@@ -245,6 +247,10 @@ function appImageUrl(v, field, where) {
   let u;
   try { u = new URL(s); } catch { fail(where, `${field} "${s}" is not a valid URL`); return undefined; }
   if (u.protocol !== 'https:') { fail(where, `${field} must be https://`); return undefined; }
+  // A /blob/ link renders an HTML page, not the image. Normalise it to the raw
+  // host so a hand-written JSON doesn't ship a broken <img> to the site.
+  const blob = s.match(/^https:\/\/github\.com\/([^/]+)\/([^/]+)\/blob\/(.+)$/);
+  if (blob) return `https://raw.githubusercontent.com/${blob[1]}/${blob[2]}/${blob[3]}`;
   if (!APP_IMAGE_HOSTS.includes(u.host)) {
     fail(where, `${field} host "${u.host}" not allowed — use one of ${APP_IMAGE_HOSTS.join(', ')}`);
     return undefined;
@@ -279,7 +285,7 @@ async function buildApps() {
     if (description.length > 280) fail(where, `description must be <=280 chars (is ${description.length})`);
 
     const platforms = (Array.isArray(json.platforms) ? json.platforms : commaList(json.platforms))
-      .map(p => String(p).trim()).filter(Boolean).map(p => p.slice(0, 24)).slice(0, 6);
+      .map(p => String(p).trim()).filter(Boolean).map(p => p.slice(0, MAX_PLATFORM_LEN)).slice(0, MAX_PLATFORMS);
 
     out.push(clean({
       slug,