Review fixes for 11.4 and 11.4b

ubuntu.sh takes Ubuntu 24.04 and its derivatives alone, since the DEB
names 24.04's t64 libraries. nixos.sh installs the newest release's
tag, not main. The release workflow refuses a tag that names another
version than the build files, and runs on the Node 24 actions.
DistortTests pins Swift's division by w past the horizon.

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

README.md

@@ -18,7 +18,7 @@ It is a Linux port of [Compositor](https://github.com/robbietilton/Compositor) b
 
 ## Install
 
-Each script downloads the newest release's package, checks it against the release's `SHA256SUMS` and installs it with your system's package manager. Packages are built for x86_64.
+Each script installs the newest release. The Arch, Ubuntu and Fedora scripts download its package, check it against the release's `SHA256SUMS` and install it with your system's package manager; the NixOS script builds the release's flake. Packages are built for x86_64.
 
 Arch and Omarchy:
 
@@ -26,13 +26,13 @@ Arch and Omarchy:
 curl -fsSLO https://raw.githubusercontent.com/ZacharyZhang-NY/OmaPhoto/main/scripts/install/arch.sh && bash arch.sh
 ```
 
-Ubuntu 24.04 or later, and its derivatives (Linux Mint 22, Pop!_OS 24.04):
+Ubuntu 24.04 LTS and systems built on it (Linux Mint 22, Pop!_OS 24.04):
 
 ```sh
 curl -fsSLO https://raw.githubusercontent.com/ZacharyZhang-NY/OmaPhoto/main/scripts/install/ubuntu.sh && bash ubuntu.sh
 ```
 
-The DEB uses Ubuntu's package names, so Debian itself builds from source (below).
+The DEB names Ubuntu 24.04's libraries, so later Ubuntu releases and Debian build from source (below).
 
 Fedora:
 
@@ -42,13 +42,13 @@ curl -fsSLO https://raw.githubusercontent.com/ZacharyZhang-NY/OmaPhoto/main/scri
 
 Fedora's own libheif decodes no HEVC. For HEIC import, add [RPM Fusion](https://rpmfusion.org/Configuration) and install `libheif-freeworld`; the script reminds you.
 
-NixOS installs from the flake into your profile:
+NixOS installs the release's flake into your profile:
 
 ```sh
 curl -fsSLO https://raw.githubusercontent.com/ZacharyZhang-NY/OmaPhoto/main/scripts/install/nixos.sh && bash nixos.sh
 ```
 
-Or add `github:ZacharyZhang-NY/OmaPhoto` as a flake input and put its `packages.x86_64-linux.default` in your configuration.
+Or add `github:ZacharyZhang-NY/OmaPhoto/<tag>`, a release tag, as a flake input and put its `packages.x86_64-linux.default` in your configuration.
 
 The packages themselves sit on the [releases page](https://github.com/ZacharyZhang-NY/OmaPhoto/releases).