v0.4.62: ship the v0.4.61 cache fix as a buildable image

v0.4.61 source landed in main with the cache fix and the
PXE-logo compositor, plus an aspirational Dockerfile stage that
rebuilds iPXE from source with IMAGE_PNG enabled. The Dockerfile
stage hits intermittent `cc1: internal compiler error: Segmentation
fault` when cross-emulating x86_64 gcc under QEMU on arm64 build
hosts, which is what the build host I was using does. No v0.4.61
image was ever published as a result.

v0.4.62 walks back the iPXE-from-source change and ships a working
image with the same cache fix and the same compositor code in place.
The iPXE rebuild is queued for a follow-up release, to be built and
validated on the actual x86_64 Unraid hardware where the QEMU
instability doesn't apply.

What's in v0.4.62 vs v0.4.6:

- Asset URL versioning: index.html now appends `?v=<openpxe-version>`
  to every asset URL (app.css, app.js, logo.svg). Combined with
  `Cache-Control: no-cache, must-revalidate` on the asset handlers,
  upgrades land in operators' browsers without a hard refresh. This
  is the fix for "I pulled v0.4.6 but the UI still looks like v0.4.5".
- New PXE-logo compositor in iso-store::pxe_logo: decodes any raster
  the operator uploads, scales-to-fit into a 600×200 bounding box,
  pastes it centered at the top of a 1024×768 PNG canvas, and serves
  the result at GET /branding/pxe-logo. Wired into render_menu's
  `console --picture` directive; takes effect when the shipped iPXE
  binaries grow PNG support.
- ASCII OpenPXE wordmark in render_menu retained for v0.4.62 — works
  on the boot.ipxe.org pre-builds we currently ship.

Quality:
- 142 tests passing.
- cargo clippy --workspace --all-targets clean.
- No image dependency change since v0.4.61 (the `image = "0.25"` dep
  added in v0.4.61 stays — it backs the compositor).

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

crates/http-api/src/ipxe_script.rs

@@ -77,15 +77,20 @@ pub fn render_menu(isos: &[IsoMeta], settings: &Settings, base_url: &str) -> Str
     );
     let _ = writeln!(s, ":menu");
     let _ = writeln!(s, "menu OpenPXE - network boot menu");
-    // v0.4.61: we used to draw an ASCII OpenPXE wordmark here. Now
-    // that the bundled iPXE is built with `IMAGE_PNG`, the
-    // `console --picture` line at the top of this script paints the
-    // operator's actual logo (composed server-side into a 1024×768
-    // canvas with the logo centered at the top) — the ASCII banner
-    // became visual noise *on top* of the real image. Old iPXE
-    // builds without PNG fall through the `|| console` clause and
-    // simply show the menu without a logo, which is the correct
-    // graceful-degradation outcome.
+    // ASCII OpenPXE wordmark. Works on every iPXE build, including
+    // the boot.ipxe.org pre-builds we ship (which omit `IMAGE_PNG`,
+    // so `console --picture` paints nothing). When the queued iPXE
+    // source-build lands and the operator's uploaded raster actually
+    // paints via `console --picture`, this banner can be retired in
+    // favour of the real image. The compositor at
+    // /branding/pxe-logo is already wired and waiting.
+    let _ = writeln!(s, "item --gap");
+    let _ = writeln!(s, "item --gap --       ___                   ___  __  __ ___");
+    let _ = writeln!(s, "item --gap --      / _ \\ _ __  ___ _ _   | _ \\ \\/  / | __|");
+    let _ = writeln!(s, "item --gap --     | (_) | '_ \\/ -_) ' \\  |  _/  \\  /  | _|");
+    let _ = writeln!(s, "item --gap --      \\___/| .__/\\___|_||_| |_|    /_/\\_\\ |___|");
+    let _ = writeln!(s, "item --gap --           |_|");
+    let _ = writeln!(s, "item --gap");
     let _ = writeln!(
         s,
         "item --gap -- ------------------------- Default -------------------------"
@@ -626,12 +631,13 @@ mod password_tests {
 
     #[test]
     fn top_menu_has_polished_branding_and_arch_footer() {
-        // v0.4.6 polish + v0.4.61 image upgrade: the menu emits a
-        // `console --picture` line that the bundled iPXE (built with
-        // `IMAGE_PNG`) honours, plus an arch-resolved footer carrying
-        // the current OpenPXE version. The ASCII wordmark that used
-        // to live here was dropped in v0.4.61 — it duplicated the now-
-        // working image.
+        // v0.4.6 polish + v0.4.62 stability fixes: the menu emits a
+        // `console --picture` line that PNG-capable iPXE builds will
+        // honour (queued for a follow-up release once we can rebuild
+        // iPXE from source on native x86_64 hardware), an ASCII
+        // OpenPXE wordmark that works on every iPXE build (including
+        // the boot.ipxe.org pre-builds we currently ship), and a
+        // single-line footer carrying the OpenPXE version + arch.
         let settings = Settings::default();
         let s = render_menu(&[], &settings, "http://10.0.0.5");
         assert!(
@@ -641,11 +647,11 @@ mod password_tests {
         // Picture-or-text-console must be a single statement so older
         // iPXE parsers don't choke on the chain.
         assert!(s.contains("|| console"), "missing graceful fallback:\n{s}");
-        // No ASCII wordmark — once the real PNG paints, the ASCII
-        // banner would duplicate the operator's logo visually.
+        // ASCII wordmark — paints on every iPXE build regardless of
+        // PNG support.
         assert!(
-            !s.contains("___                   ___  __  __ ___"),
-            "ASCII banner shouldn't be emitted in v0.4.61+:\n{s}"
+            s.contains("___                   ___  __  __ ___"),
+            "ASCII banner missing first row:\n{s}"
         );
         // Footer with version + arch interpolation. The version comes
         // from CARGO_PKG_VERSION at compile time.