chore: point svemagie fork deps and docs at Gitea

- Switch 4 svemagie fork deps from github: shorthand to git+https://gitea.giersig.eu/svemagie/...
- Add patch-store-github-error-message.mjs to replace hardcoded github.com token URL with gitea.giersig.eu
- Update CLAUDE.md and README.md fork dependency docs

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

scripts/patch-store-github-error-message.mjs

@@ -0,0 +1,55 @@
+import { access, readFile, writeFile } from "node:fs/promises";
+
+const candidates = [
+  "node_modules/@indiekit/store-github/index.js",
+];
+
+const MARKER = "// [patched] store-github-error-message";
+
+const OLD_SNIPPET = `    \`Ensure the GitHub token is not expired and has the necessary permissions\`,
+    \`You can check your tokens here: https://github.com/settings/tokens\`,`;
+
+const NEW_SNIPPET = `    \`Ensure the Gitea token is not expired and has the necessary permissions\`,
+    \`You can check your tokens here: https://gitea.giersig.eu/user/settings/applications\`, ${MARKER}`;
+
+async function exists(path) {
+  try {
+    await access(path);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+let checked = 0;
+let patched = 0;
+
+for (const filePath of candidates) {
+  if (!(await exists(filePath))) {
+    continue;
+  }
+
+  checked += 1;
+
+  const source = await readFile(filePath, "utf8");
+
+  if (source.includes(MARKER)) {
+    console.log("[postinstall] store-github error message already patched");
+    continue;
+  }
+
+  if (!source.includes(OLD_SNIPPET)) {
+    console.warn("[postinstall] store-github: unexpected source layout, skipping");
+    continue;
+  }
+
+  const updated = source.replace(OLD_SNIPPET, NEW_SNIPPET);
+  await writeFile(filePath, updated, "utf8");
+  patched += 1;
+}
+
+if (checked === 0) {
+  console.log("[postinstall] No store-github index.js found");
+} else if (patched > 0) {
+  console.log(`[postinstall] Patched store-github error message in ${patched} file(s)`);
+}