Stop linking the Android APK through a branch-named raw URL.

Co-authored-by: Cursor <cursoragent@cursor.com>

README.md

@@ -30,7 +30,7 @@ větve.
 | macOS (Apple Silicon) | [maturita-installer-macos.zip](https://github.com/pepaskopec-blip/maturita.c/raw/main/installers/maturita-installer-macos.zip) | Rozbalit, pravý klik na **Nainstalovat maturita.C** → **Otevřít** |
 | Windows (x64) | [maturita-installer-windows.zip](https://github.com/pepaskopec-blip/maturita.c/raw/main/installers/maturita-installer-windows.zip) | Rozbalit a dvojklik; u SmartScreenu **Další informace → Přesto spustit** |
 | Linux (x86_64) | [maturita-installer-linux.zip](https://github.com/pepaskopec-blip/maturita.c/raw/main/installers/maturita-installer-linux.zip) | Rozbalit a dvojklik na instalátor |
-| Android (8+) | [maturita-android.apk](https://github.com/pepaskopec-blip/maturita.c/raw/builds/maturita-android.apk) | Stáhnout APK a nainstalovat (neznámé zdroje) |
+| Android (8+) | [maturita-installer-android.zip](https://github.com/pepaskopec-blip/maturita.c/raw/main/installers/maturita-installer-android.zip) | Rozbalit, otevřít **Stahnout maturita.C.html** a nainstalovat APK (neznámé zdroje) |
 
 Kam se to nainstaluje: `/Applications` nebo `~/Applications` (macOS),
 `%LOCALAPPDATA%\Programs\Maturita` (Windows), `~/Applications` (Linux).
@@ -50,7 +50,7 @@ spolehlivější instalátor výše, nebo stažení přímo z té stránky větv
 - [maturita-macos-arm64.zip](https://github.com/pepaskopec-blip/maturita.c/raw/builds/maturita-macos-arm64.zip)
 - [maturita-windows-x64.zip](https://github.com/pepaskopec-blip/maturita.c/raw/builds/maturita-windows-x64.zip)
 - [maturita-linux-x86_64.AppImage](https://github.com/pepaskopec-blip/maturita.c/raw/builds/maturita-linux-x86_64.AppImage)
-- [maturita-android.apk](https://github.com/pepaskopec-blip/maturita.c/raw/builds/maturita-android.apk)
+- [maturita-android.apk](https://github.com/pepaskopec-blip/maturita.c/raw/refs/heads/builds/maturita-android.apk)
 
 Postup a nastavení se ukládají vedle `.app` / složky / AppImage do `progress/`.
 Na Androidu do úložiště aplikace (stejné statistiky, témata a jazyk).
@@ -180,7 +180,7 @@ branch-named file.
 | macOS (Apple Silicon) | [maturita-installer-macos.zip](https://github.com/pepaskopec-blip/maturita.c/raw/main/installers/maturita-installer-macos.zip) | Unzip, right-click **Nainstalovat maturita.C** → **Open** |
 | Windows (x64) | [maturita-installer-windows.zip](https://github.com/pepaskopec-blip/maturita.c/raw/main/installers/maturita-installer-windows.zip) | Unzip and double-click; if SmartScreen appears, **More info → Run anyway** |
 | Linux (x86_64) | [maturita-installer-linux.zip](https://github.com/pepaskopec-blip/maturita.c/raw/main/installers/maturita-installer-linux.zip) | Unzip and double-click the installer |
-| Android (8+) | [maturita-android.apk](https://github.com/pepaskopec-blip/maturita.c/raw/builds/maturita-android.apk) | Download the APK and install (unknown sources) |
+| Android (8+) | [maturita-installer-android.zip](https://github.com/pepaskopec-blip/maturita.c/raw/main/installers/maturita-installer-android.zip) | Unzip, open **Stahnout maturita.C.html**, then install the APK (unknown sources) |
 
 Install locations: `/Applications` or `~/Applications` (macOS),
 `%LOCALAPPDATA%\Programs\Maturita` (Windows), `~/Applications` (Linux).
@@ -200,7 +200,7 @@ above, or download from that branch page:
 - [maturita-macos-arm64.zip](https://github.com/pepaskopec-blip/maturita.c/raw/builds/maturita-macos-arm64.zip)
 - [maturita-windows-x64.zip](https://github.com/pepaskopec-blip/maturita.c/raw/builds/maturita-windows-x64.zip)
 - [maturita-linux-x86_64.AppImage](https://github.com/pepaskopec-blip/maturita.c/raw/builds/maturita-linux-x86_64.AppImage)
-- [maturita-android.apk](https://github.com/pepaskopec-blip/maturita.c/raw/builds/maturita-android.apk)
+- [maturita-android.apk](https://github.com/pepaskopec-blip/maturita.c/raw/refs/heads/builds/maturita-android.apk)
 
 Progress and settings live in `progress/` next to the `.app` / folder /
 AppImage. On Android they stay in app storage (same stats, themes, language).

installers/maturita-android.html

@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<html lang="cs">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>Stáhnout maturita.C</title>
+  <style>
+    body {
+      font-family: system-ui, sans-serif;
+      max-width: 28rem;
+      margin: 3rem auto;
+      padding: 0 1.2rem;
+      color: #1a1a1a;
+    }
+    a.btn {
+      display: block;
+      text-align: center;
+      background: #1a1a1a;
+      color: #fff;
+      padding: 1rem 1.2rem;
+      border-radius: 999px;
+      text-decoration: none;
+      font-weight: 600;
+    }
+    p { color: #444; line-height: 1.45; }
+    code { font-size: 0.95em; }
+  </style>
+</head>
+<body>
+  <h1>maturita.C pro Android</h1>
+  <p>Klepni na tlačítko. Až se APK stáhne, otevři ho a povol instalaci z neznámých zdrojů.</p>
+  <p>
+    <a class="btn" id="dl"
+       href="https://raw.githubusercontent.com/pepaskopec-blip/maturita.c/refs/heads/builds/maturita-android.apk">
+      Stáhnout APK
+    </a>
+  </p>
+  <p>
+    Když odkaz hlásí 404, otevři
+    <a href="https://github.com/pepaskopec-blip/maturita.c/tree/builds">větev builds</a>
+    a stáhni <code>maturita-android.apk</code> odtud.
+  </p>
+  <script>
+    (function () {
+      var repo = "pepaskopec-blip/maturita.c";
+      fetch("https://api.github.com/repos/" + repo + "/commits/builds")
+        .then(function (r) { return r.json(); })
+        .then(function (d) {
+          if (d && d.sha) {
+            document.getElementById("dl").href =
+              "https://raw.githubusercontent.com/" + repo + "/" + d.sha + "/maturita-android.apk";
+          }
+        })
+        .catch(function () {});
+    })();
+  </script>
+</body>
+</html>

installers/pack-installer-zips.sh

@@ -1,6 +1,6 @@
 #!/bin/sh
-# Rebuild the three installer zips that README links to. Browsers download a
+# Rebuild the installer zips that README links to. Browsers download a
-# zip; they render .command / .sh / .cmd as a text tab.
+# zip; they render .command / .sh / .cmd / .html as a text tab.
 
 set -eu
 
@@ -24,3 +24,11 @@ rm -f "$here/maturita-installer-macos.zip"
 
 zip -q -FS maturita-installer-windows.zip maturita-installer-windows.cmd
 zip -q -FS maturita-installer-linux.zip maturita-installer-linux.sh
+
+# Browsers download a zip; they render .html as a text tab on GitHub.
+# The page looks up the tip of `builds` so Fastly cannot serve a cached 404
+# for the branch-named APK URL.
+cp maturita-android.html "$tmp/Stahnout maturita.C.html"
+rm -f "$here/maturita-installer-android.zip"
+(cd "$tmp" && zip -q -FS "$here/maturita-installer-android.zip" \
+    "Stahnout maturita.C.html")