1.4.0: not_found, server-only response options, compression

- Server functions can return not_found: true to render the 404 page
  with status 404.
- Page components and window.__PAGE_PROPS__ (and HMR updates) only get
  props, query, url and error. response_options, redirect, cache settings
  and res_transform stay on the server, so cookies and private headers no
  longer end up in the HTML. BunextPageProps is narrowed to match
  (breaking for code that read server-only fields from component props).
- response_options headers go through a Headers object, so repeated
  headers such as several Set-Cookie survive.
- Redirects: status_code wins over permanent; response_options headers
  and res_transform apply to redirects too.
- Gzip for compressible text responses; compress: false to turn it off.
- Files the router matches but never bundles (.server.ts, __root,
  excluded paths and directories) return 404 instead of looping through
  dev rebuild retries.
- Missing public files return 404 rather than 403, so dotted page paths
  like /users/john.doe fall through to pages again.
- importFresh detects rewrites within the filesystem's mtime granularity.
- README: self-hosted React (not esm.sh), snake_case option names, static
  file serving, cache headers, the new options.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

dist/utils/is-routable-page.js

@@ -0,0 +1,39 @@
+import path from "path";
+import AppNames from "./grab-app-names";
+import checkExcludedPatterns from "./check-excluded-patterns";
+import grabDirNames from "./grab-dir-names";
+/**
+ * Whether a file matched by the FileSystemRouter is actually a page.
+ *
+ * `Bun.FileSystemRouter` routes every file under `src/pages`, including
+ * ones the bundler never builds: `.server.ts` companions, the `__root`
+ * layout, tests, and paths excluded by `pages_exclude_patterns` (or inside
+ * an excluded directory). Requests for those must 404 rather than wait for
+ * a bundle that will never exist. Mirrors the rules in `grabAllPages`.
+ */
+export default function isRoutablePage(file_path) {
+    const { PAGES_DIR } = grabDirNames();
+    const file_name = path.basename(file_path);
+    if (/\.server\.(t|j)sx?$/.test(file_name))
+        return false;
+    if (/\.test\.(t|j)sx?$/.test(file_name))
+        return false;
+    if (/__tests__/.test(file_path))
+        return false;
+    if (file_name.match(new RegExp(AppNames["RootPagesComponentName"]))) {
+        return false;
+    }
+    // grabAllPages skips an excluded directory without looking inside it,
+    // so check every directory between PAGES_DIR and the file as well.
+    const relative = path.relative(PAGES_DIR, file_path);
+    if (relative.startsWith("..") || path.isAbsolute(relative)) {
+        return !checkExcludedPatterns({ path: file_path });
+    }
+    let current = PAGES_DIR;
+    for (const segment of relative.split(path.sep)) {
+        current = path.join(current, segment);
+        if (checkExcludedPatterns({ path: current }))
+            return false;
+    }
+    return true;
+}