feat(install): registry-only path, drop paru --pkgbuilds from setup

post-install.sh and transform.sh no longer write paru.conf entries for
the PKGBUILD repo — the Arch registry is the single source of truth.
pacman -Sy + paru -S moonarch-git now suffices. See DECISIONS.md.

DECISIONS.md

@@ -1,5 +1,11 @@
 # Decisions
 
+## 2026-04-20 – Registry-only install: drop paru --pkgbuilds from setup scripts
+- **Who**: Dominik, ClaudeCode
+- **Why**: Two parallel paths for finding moonarch packages (Arch registry via `[moonarch]` in pacman.conf, and paru's PKGBUILD-repo via `[moonarch-pkgbuilds]` in paru.conf) caused ambiguity during debugging: `paru -S moonarch-git` was resolving against the registry's stale DB (zombie r99 entry) while the PKGBUILD source would have had r105. Also: the PKGBUILD-repo path triggered a local build on every client, while the registry ships prebuilt binaries. With the registry DB now stable (see `moonarch-pkgbuilds/DECISIONS.md`, same date), the second mechanism is redundant.
+- **Tradeoffs**: If the registry is down or broken, clients have no local-build fallback. Acceptable — a broken registry is a server-side bug to fix, not something to mask with a parallel mechanism that complicates diagnostics.
+- **How**: `post-install.sh` and `transform.sh` no longer write `Mode = arp` or a `[moonarch-pkgbuilds]` section to `/etc/paru.conf`, and no longer call `paru -Syu --pkgbuilds`. They run `pacman -Sy` + `paru -S moonarch-git` against the registry. The `moonarch-git` install hook now strips the legacy paru.conf entries on upgrade (see moonarch-pkgbuilds repo).
+
 ## 2026-04-19 – moonup i18n: reuse pacman gettext catalog + inline fallback
 - **Who**: Dominik, ClaudeCode
 - **Why**: moonup prompts looked foreign next to pacman/paru output (`[y/N]` vs `[J/n]`, English strings on a German system). User wanted consistency with the rest of the pacman UX.

scripts/post-install.sh

@@ -60,29 +60,10 @@ fi
 rm -f "$KEY_FILE"
 trap - EXIT
 
-# --- Set up Moonarch custom paru repo (needed for first install bootstrap) ---
-
-log "Setting up Moonarch paru repo..."
-PARU_CONF="/etc/paru.conf"
-if ! grep -q 'Mode.*p' "$PARU_CONF" 2>/dev/null; then
-    sudo sed -i '/^\[options\]/a Mode = arp' "$PARU_CONF"
-    log "  + Mode = arp set in paru.conf."
-else
-    log "  ~ Mode already includes pkgbuilds."
-fi
-if ! grep -q '\[moonarch-pkgbuilds\]' "$PARU_CONF" 2>/dev/null; then
-    printf '\n[moonarch-pkgbuilds]\nUrl = https://gitea.moonarch.de/nevaforget/moonarch-pkgbuilds.git\n' \
-        | sudo tee -a "$PARU_CONF" > /dev/null
-    log "  + Moonarch repo added to paru.conf."
-else
-    log "  ~ Moonarch repo already in paru.conf."
-fi
-
-paru -Syu --pkgbuilds --noconfirm
-
-# --- Install moonarch-git (subsequent updates handled by moonarch.install hook) ---
+# --- Install moonarch-git from the Arch registry ---
 
 log "Installing moonarch-git package..."
+sudo pacman -Sy --noconfirm
 paru -S --needed --noconfirm moonarch-git
 
 # --- User-level GTK4 symlinks for libadwaita apps ---

scripts/transform.sh

@@ -245,10 +245,8 @@ fi
 rm -f "$KEY_FILE"
 trap - EXIT
 
-# Install/update moonarch-git (paru repo config is set up by moonarch.install hook)
-paru -Syu --pkgbuilds --noconfirm
-
 log "Installing moonarch-git package..."
+sudo pacman -Sy --noconfirm
 paru -S --needed --noconfirm moonarch-git
 
 # Install packages from package lists