diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1afa2b0..6219672 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,6 +5,9 @@ on:
     branches: [main]
   pull_request:
 
+permissions:
+  contents: read
+
 concurrency:
   group: ci-${{ github.ref }}
   cancel-in-progress: true
diff --git a/app/src/components/launchpad/image-upload.test.ts b/app/src/components/launchpad/image-upload.test.ts
new file mode 100644
index 0000000..06fe572
--- /dev/null
+++ b/app/src/components/launchpad/image-upload.test.ts
@@ -0,0 +1,83 @@
+import assert from "node:assert/strict";
+import { spawnSync } from "node:child_process";
+import test from "node:test";
+import { fileURLToPath } from "node:url";
+
+type PreviewInput = { value: string; compact?: boolean };
+
+/**
+ * Render the real client component and React's attribute serializer. The main
+ * test command selects react-server exports, so this child deliberately starts
+ * without that condition: useState/useRef and react-dom/server need the normal
+ * React entry points. Static rendering performs no image requests or uploads.
+ */
+function renderPreviews(inputs: PreviewInput[]): string[] {
+  const result = spawnSync(process.execPath, ["--import", "tsx", "--eval", `
+    const { readFileSync } = require("node:fs");
+    const { createElement } = require("react");
+    const { renderToStaticMarkup } = require("react-dom/server");
+    const ImageUpload = require("./src/components/launchpad/ImageUpload.tsx").default;
+    const inputs = JSON.parse(readFileSync(0, "utf8"));
+    const output = inputs.map((props) => renderToStaticMarkup(createElement(ImageUpload, {
+      ...props, wallet: undefined, onChange() { throw new Error("Rendering must not upload or change the URL"); },
+    })));
+    process.stdout.write(JSON.stringify(output));
+  `], {
+    cwd: fileURLToPath(new URL("../../../", import.meta.url)),
+    input: JSON.stringify(inputs),
+    encoding: "utf8",
+    timeout: 10_000,
+    windowsHide: true,
+  });
+  assert.ifError(result.error);
+  assert.equal(result.status, 0, result.stderr);
+  return JSON.parse(result.stdout) as string[];
+}
+
+test("image previews retain HTTP(S), trim whitespace, and preserve compact sizing", () => {
+  const [https, http, compact] = renderPreviews([
+    { value: "  https://images.example/logo.png  " },
+    { value: "http://images.example/logo.gif" },
+    { value: "https://images.example/logo.webp", compact: true },
+  ]);
+  assert.ok(https.includes('<img src="https://images.example/logo.png"'));
+  assert.ok(http.includes('<img src="http://images.example/logo.gif"'));
+  assert.ok(compact.includes('<img src="https://images.example/logo.webp"'));
+  assert.ok(https.includes('width="88" height="88"'));
+  assert.ok(compact.includes('width="64" height="64"'));
+  for (const html of [https, http, compact]) {
+    assert.ok(html.includes('referrerPolicy="no-referrer"'));
+    assert.ok(html.includes(">Change image</p>"));
+  }
+});
+
+test("non-HTTP(S) input never becomes an image preview", () => {
+  const values = [
+    "", "  ",
+    "javascript:alert(1)", " \tjavascript:alert(1)\n",
+    "JaVaScRiPt:alert(1)", "java\nscript:alert(1)",
+    "data:text/html,<script>alert(1)</script>",
+    "data:image/svg+xml,<svg onload=alert(1)></svg>",
+    "//images.example/logo.png", "/logo.png", "https:images.example/logo.png",
+    '"/><img src=x onerror="alert(1)">',
+  ];
+  const output = renderPreviews(values.map((value) => ({ value })));
+  for (const [index, html] of output.entries()) {
+    assert.equal(html.includes("<img"), false, `Unexpected preview for ${JSON.stringify(values[index])}`);
+    assert.equal(html.includes("<script"), false);
+    assert.ok(html.includes(">Upload image</p>"));
+  }
+});
+
+test("quotes and markup in an HTTP(S) URL remain encoded attribute data", () => {
+  const value = 'https://images.example/logo.png?x=" onerror="alert(1)"><script>alert(2)</script>&y=\'test\'';
+  const escaped = "https://images.example/logo.png?x=&quot; onerror=&quot;alert(1)&quot;&gt;&lt;script&gt;alert(2)&lt;/script&gt;&amp;y=&#x27;test&#x27;";
+  const [html] = renderPreviews([{ value }]);
+  // Assert the actual serialized sink, not a duplicate sanitization function or
+  // a source-code pattern. React must keep the entire value in one src attribute.
+  assert.ok(html.includes(`<img src="${escaped}" alt=""`));
+  assert.ok(html.includes(`value="${escaped}"`));
+  assert.equal(html.includes(' onerror="'), false);
+  assert.equal(html.includes("<script>"), false);
+  assert.equal(html.includes("</script>"), false);
+});
diff --git a/app/src/lib/ci-permissions.test.ts b/app/src/lib/ci-permissions.test.ts
new file mode 100644
index 0000000..f4deee1
--- /dev/null
+++ b/app/src/lib/ci-permissions.test.ts
@@ -0,0 +1,11 @@
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import test from "node:test";
+
+test("build-only CI declares read-only token permissions for both jobs", () => {
+  const workflow = readFileSync(new URL("../../../.github/workflows/ci.yml", import.meta.url), "utf8");
+  const permissions = workflow.match(/^permissions:[ \t]*\r?\n((?:[ \t]+[^\r\n]*\r?\n)+)/m)?.[1];
+  assert.ok(permissions, "CI must explicitly declare workflow-level token permissions");
+  assert.deepEqual(permissions.trim().split(/\r?\n/).map((line) => line.trim()), ["contents: read"]);
+  assert.equal([...workflow.matchAll(/^[ \t]*permissions:/gm)].length, 1, "both jobs inherit the read-only policy without overrides");
+});
diff --git a/app/src/lib/launchpad/posts.test.ts b/app/src/lib/launchpad/posts.test.ts
index 81afb11..458337e 100644
--- a/app/src/lib/launchpad/posts.test.ts
+++ b/app/src/lib/launchpad/posts.test.ts
@@ -25,6 +25,50 @@ test("post message binds chain, token, wallet, reply, nonce, time and body", ()
   assert.ok(buildModMessage({ action: "hide", target: "post:3", wallet: "0xCD", nonce: "n", ts: 0 }).includes("Action: hide"));
 });
 
+test("validateBody preserves every code unit except the intended controls and CR normalization", () => {
+  for (let unit = 0; unit <= 0xffff; unit++) {
+    const character = String.fromCharCode(unit);
+    const stripped = unit <= 0x08 || unit === 0x0b || unit === 0x0c
+      || (unit >= 0x0e && unit <= 0x1f) || unit === 0x7f;
+    const expected = stripped ? "" : unit === 0x0d ? "\n" : character;
+    // Sentinels keep whitespace inside the body, independent of edge trimming.
+    assert.deepEqual(validateBody(`a${character}z`), { ok: true, body: `a${expected}z` }, `code unit ${unit.toString(16)}`);
+  }
+});
+
+test("validateBody retains text whitespace and Unicode while normalizing line endings", () => {
+  assert.deepEqual(validateBody(" \tfirst\tsecond\r\nthird\rfourth\n\n\nfifth\t "), {
+    ok: true,
+    body: "first\tsecond\nthird\nfourth\n\nfifth",
+  });
+  const unicode = "தமிழ் café e\u0301 👩‍💻 🚀 — \u200b\u0085\u009f";
+  assert.deepEqual(validateBody(unicode), { ok: true, body: unicode });
+  assert.deepEqual(validateBody("a\u0000b\u0007c\u0008d\u000be\u000cf\u000eg\u001fh\u007f"), {
+    ok: true,
+    body: "abcdefgh",
+  });
+  assert.deepEqual(validateBody("\u0000\u0008\u000b\u000c\u000e\u001f\u007f"), { ok: false, error: "empty post" });
+  assert.deepEqual(validateBody("x".repeat(500) + "\u0000\u001f\u007f"), { ok: true, body: "x".repeat(500) });
+});
+
+test("normalized post bodies retain their byte-exact signed message", () => {
+  const result = validateBody(" \tgm\u0000\tfrens\r\nதமிழ் 🚀 — open\u007f ");
+  assert.equal(result.ok, true);
+  if (!result.ok) return;
+  assert.equal(buildPostMessage({ chain: "base", token: "0xAB", wallet: "0xCD", nonce: "n", ts: 0, parentId: 7, body: result.body }), [
+    "openlaunch.lol \u2014 sign to post. Free, no transaction.",
+    "",
+    "Chain: base",
+    "Token: 0xab",
+    "Wallet: 0xcd",
+    "Reply to: 7",
+    "Nonce: n",
+    "Time: 1970-01-01T00:00:00.000Z",
+    "",
+    "gm\tfrens\nதமிழ் 🚀 — open",
+  ].join("\n"));
+});
+
 test("copy cleanup preserves byte-exact wallet signature headers and user text", () => {
   const body = "hello \u2014 world";
   const message = buildPostMessage({ chain: "base", token: "0xAB", wallet: "0xCD", nonce: "n", ts: 0, parentId: null, body });
diff --git a/app/src/lib/launchpad/posts.ts b/app/src/lib/launchpad/posts.ts
index 881bf81..b6deaaa 100644
Binary files a/app/src/lib/launchpad/posts.ts and b/app/src/lib/launchpad/posts.ts differ
diff --git a/app/src/lib/seo.test.ts b/app/src/lib/seo.test.ts
index 5888a3c..e0c2db7 100644
--- a/app/src/lib/seo.test.ts
+++ b/app/src/lib/seo.test.ts
@@ -42,7 +42,9 @@ test("static sitemap covers every public route and skips /admin", () => {
   assert.ok(!paths.includes("/admin"), "/admin must stay out of the sitemap");
   const entries = staticSitemapEntries(SITE, "2026-09-06T00:00:00.000Z");
   assert.equal(entries.length, STATIC_SITEMAP_ROUTES.length);
-  assert.ok(entries.every((e) => e.url.startsWith(SITE)));
+  for (const entry of entries) {
+    assert.equal(new URL(entry.url).origin, new URL(SITE).origin);
+  }
   assert.equal(entries[0].url, `${SITE}/`);
 });