app installer hrefs + IIS /installers static

deploy/windows/web.config

@@ -76,4 +76,39 @@
     -->
 
   </system.webServer>
+
+  <!--
+    Installer downloads: serve /installers/* as IIS static files instead of
+    forwarding them to Flask. The handler above is path="*", so without this a
+    request for /installers/Foo.exe goes to waitress, which has no such route
+    (SPA fallback), and large binaries would stream through a Python thread.
+
+    This <location> clears the httpPlatformHandler for that one subpath and puts
+    the static file handler back, so IIS serves the bytes directly (kernel-mode,
+    range/resume, no Python thread held).
+
+    Requires a physical folder at APP_ROOT\installers (the site's physical path
+    is APP_ROOT). Drop the installer binaries there, e.g. robocopy them from the
+    classic wwwroot\installers. The stored installpath 'installers/Foo.exe' then
+    resolves to <mount>/installers/Foo.exe (e.g. /shopdb/installers/Foo.exe).
+
+    .exe/.msi are given an explicit MIME map; if the parent site has a Request
+    Filtering rule that denies executable extensions, also allow them there.
+  -->
+  <location path="installers">
+    <system.webServer>
+      <handlers>
+        <clear />
+        <add name="StaticFile" path="*" verb="*"
+             modules="StaticFileModule" resourceType="File"
+             requireAccess="Read" />
+      </handlers>
+      <staticContent>
+        <remove fileExtension=".exe" />
+        <mimeMap fileExtension=".exe" mimeType="application/octet-stream" />
+        <remove fileExtension=".msi" />
+        <mimeMap fileExtension=".msi" mimeType="application/octet-stream" />
+      </staticContent>
+    </system.webServer>
+  </location>
 </configuration>