docs: rework all pages to Artix Wiki quality

- index.md: add download link + stable release announcement
- building.md: add troubleshooting section (cache, squashfs, compression)
- ci.md: IA upload enabled, push trigger removed (manual dispatch only)
- development.md: add all gotchas from AGENTS.md (SDDM theme ordering,
  pipewire launcher, antergos-release in basestrap, CI changes)
- installer.md: document fixed issues (audio, SDDM, os-release)
- packages.md: add pipewire fork, antergos-sddm-theme, antergos-release
- launcher.md: expand with module configs
- init-systems.md: Chimera uses dinit, OpenRC marked as broken
- openrc.md: add broken warning banner
- wallpapers.md: default is antergos-wallpaper.png (not Adwaita Morning)
- overlays: clean up explanations and symlink behavior
- desktop-environments.md: add Discover note, clean up GNOME entry
- dinit.md, runit.md, s6.md: polish and add troubleshooting sections

docs/building.md

@@ -6,7 +6,7 @@ nav_order: 2
 
 # Building the ISO
 
-Requires an **Artix-based** system with `artools` and `squashfs-tools`.
+The ISO is built with `buildiso` (from Artix `artools` package) plus a customized profile. You need an **Artix-based** system to build.
 
 ## Prerequisites
 
@@ -15,6 +15,8 @@ pacman -S artools squashfs-tools
 modprobe loop
 ```
 
+`squashfs-tools` is needed for `mksquashfs`. The `loop` module must be loaded for `mount -o loop` during image assembly.
+
 ## Clone and configure
 
 ```bash
@@ -28,30 +30,105 @@ mkdir -p ~/.config/artools/pacman.conf.d
 cp pacman.conf.d/iso-x86_64.conf ~/.config/artools/pacman.conf.d/
 ```
 
+Without this override, `buildiso` uses `/usr/share/artools/pacman.conf.d/iso-x86_64.conf` (from the artools package), which lacks the `[antergos-pkgs]` repository. The build will then try to fetch our custom packages (branding, Calamares config, wallpapers) from Artix repos and fail.
+
 ## Build
 
 ```bash
 sudo -E ./buildiso -p antergos
 ```
 
-> **⚠️ Use `./buildiso`, not `buildiso`.** The Artix system `/usr/bin/buildiso` lacks the `--overwrite='*'` flag, causing file conflicts between `calamares` and `calamares-branding-antergos-next` (both claim `/usr/share/calamares/branding/default/`). Our repo's `./buildiso` has it.
+- **Use `./buildiso`**, not `buildiso`. The system `/usr/bin/buildiso` lacks `--overwrite='*'`, which causes file conflicts between `calamares` and `calamares-branding-antergos-next` (both claim `/usr/share/calamares/branding/default/`). Our repo's `./buildiso` has it.
+- **`sudo -E`** is required. Without `-E`, `WORKSPACE_DIR` is stripped and `load_profile()` returns empty `HAS_LIVE`/`LIVEUSER`, causing the build to fail early.
 
 ## Output
 
-The ISO appears in `/var/lib/artools/buildiso/iso/antergos/`.
+The ISO appears in `/var/lib/artools/buildiso/iso/antergos/`:
 
-First build pulls ~5 GB from the internet. Subsequent builds use pacman cache. Go make a coffee. Or two. Maybe three.
+```
+/var/lib/artools/buildiso/iso/antergos/
+├── antergos-<date>.iso       # Bootable ISO
+└── antergos-<date>.sha1sum   # Checksum
+```
+
+First build pulls ~5 GB from the internet (package downloads). Subsequent builds use pacman cache.
 
 ## Environment variables
 
 | Variable | Purpose |
 |----------|---------|
 | `WORKSPACE_DIR` | Must point to repo root. `buildiso` looks for profiles under `$WORKSPACE_DIR/iso-profiles/` |
-| `COMPRESSION` | Squashfs compression type (e.g. `zstd`). If unset, `mksquashfs` fails silently with a zero-size image |
+| `COMPRESSION` | Squashfs compression type (e.g. `zstd`, `gzip`, `xz`). If unset, `mksquashfs` produces a zero-size sparse file instead of a valid squashfs |
 
-## Custom packages repo
+## Troubleshooting
 
-The ISO pulls branding, Calamares config, and wallpapers from our custom repo. To use it on your system:
+### "File conflict" errors during build
+
+This means `--overwrite='*'` is not being passed to `basestrap`. Make sure you're using the repo's `./buildiso`, not the system one:
+
+```bash
+# Wrong — system buildiso without --overwrite:
+buildiso -p antergos
+
+# Correct:
+./buildiso -p antergos
+```
+
+### Build fails with "HAS_LIVE is empty"
+
+Forgetting `sudo -E`:
+
+```bash
+# Wrong — WORKSPACE_DIR not preserved:
+sudo ./buildiso -p antergos
+
+# Correct:
+sudo -E ./buildiso -p antergos
+```
+
+### buildiso can't find our custom repo
+
+The pacman config override is missing:
+
+```bash
+mkdir -p ~/.config/artools/pacman.conf.d
+cp pacman.conf.d/iso-x86_64.conf ~/.config/artools/pacman.conf.d/
+```
+
+### Zero-size squashfs (ISO exists but is tiny)
+
+`$COMPRESSION` is unset. Either set it in `profile.yaml` or pass it via environment:
+
+```bash
+export COMPRESSION=zstd
+sudo -E ./buildiso -p antergos
+```
+
+Remove the stale image before retrying:
+
+```bash
+rm -rf /var/lib/artools/buildiso/iso/antergos/
+```
+
+### Corrupted pacman cache
+
+If `basestrap` fails with checksum errors, clear the cache:
+
+```bash
+rm -rf /var/lib/artools/buildiso/pkg/antergos/cache/
+```
+
+Then rebuild.
+
+## CI builds
+
+The CI pipeline (`.github/workflows/build.yml`) handles all of the above automatically. It runs in an Artix container, sets `WORKSPACE_DIR`, overrides pacman config, mounts a 12 GB tmpfs, and uploads the resulting ISO to the Internet Archive.
+
+Trigger CI manually from the GitHub Actions tab (push trigger is disabled).
+
+## Local pacman repo
+
+To use the custom packages repo on an installed system:
 
 ```ini
 [antergos-pkgs]