fix(fonts): repair Waybar font and add system-wide fontconfig defaults

Nerd Fonts renamed "Ubuntu" -> "UbuntuSans"; Waybar's dead family name token-matched to Hack. Correct the explicit name and ship owned conf.d defaults mapping the generic families to the moonarch fonts.

- waybar/style.css: "Ubuntu Nerd Font" -> "UbuntuSans Nerd Font"
- conf.d/65-moonarch-fonts.conf: sans-serif/monospace, binding="strong" (weak prefer ranks behind the generic fallback)
- document fontconfig defaults in CLAUDE.md and DECISIONS.md

CLAUDE.md

@@ -63,6 +63,14 @@ Diagnose-Script das den Systemzustand gegen moonarch-Defaults prüft:
 - System-Config (UFW, Pacman/Paru Repos, Default Shell)
 - Verzeichnisse + Permissions
 
+## Fontconfig Defaults
+
+Systemweite generic-family Defaults via `defaults/etc/fonts/conf.d/65-moonarch-fonts.conf` (owned by moonarch-git):
+- `sans-serif` → UbuntuSans Nerd Font, `monospace` → UbuntuSansMono Nerd Font
+- Nummer **65**: lädt nach `60-latin.conf`, sodass die moonarch-Prefs den Stock-Default (Noto/DejaVu) schlagen. `local.conf` (bei 51 via `51-local.conf`) lädt zu früh und wird von 60-latin überstimmt — daher **nicht** verwenden (außerdem für lokale User-Overrides reserviert).
+- Aliases brauchen `binding="strong"` — ein weak `<prefer>` (fontconfig-Default) rankt hinter dem effektiven generischen Fallback und greift nicht.
+- Greift nur für Apps die generische Familien nutzen (z.B. Firefox-Web-Fallback). moonarch-Apps (Waybar, foot, GTK, walker, swaync) setzen den Font explizit.
+
 ## Konventionen
 
 - Paketlisten sind einfache Textdateien, ein Paket pro Zeile, Kommentare mit `#`

DECISIONS.md

@@ -1,5 +1,11 @@
 # Decisions
 
+## 2026-06-08 – Fontconfig generic-family defaults via owned conf.d (65)
+- **Who**: Dominik, ClaudeCode
+- **Why**: Waybar rendered in Hack instead of Ubuntu after the Nerd Fonts "Ubuntu"→"UbuntuSans" rename (Canonical rebrand). Waybar's style.css referenced the now-dead family "Ubuntu Nerd Font"; fontconfig token-matched it to "Hack Nerd Font". An unowned hand-written `/etc/fonts/local.conf` additionally pinned sans-serif/monospace to Hack — a stale relic.
+- **Tradeoffs**: `local.conf` (loaded at 51 via `51-local.conf`) is structurally too early — `60-latin.conf` prepends Noto/DejaVu afterwards and wins, so its sans-serif pin never took effect. local.conf is also reserved for local admin overrides, and packaging it as owned would collide with pre-existing unowned files on pacman update. A conf.d file at 65 loads after 60-latin (convention: 60–69 = generic→family) and wins cleanly without conflict.
+- **How**: New owned `defaults/etc/fonts/conf.d/65-moonarch-fonts.conf` maps sans-serif→UbuntuSans Nerd Font, monospace→UbuntuSansMono Nerd Font; installed by moonarch-git PKGBUILD. Stale `/etc/fonts/local.conf` removed. Waybar `style.css` font-family corrected "Ubuntu Nerd Font"→"UbuntuSans Nerd Font" (the bar wants the explicit proportional font, not a generic). The aliases need `binding="strong"` — verified that a weak `<prefer>` (fontconfig's default for `<alias>`) ranks behind the system's effective generic fallback and does not take effect; strong is required for it to apply.
+
 ## 2026-05-04 – Nightlight default OFF, no global enablement
 
 - **Who**: Dominik, ClaudeCode

defaults/etc/fonts/conf.d/65-moonarch-fonts.conf

@@ -0,0 +1,21 @@
+<?xml version="1.0"?>
+<!-- ABOUTME: System-wide fontconfig generic-family defaults for Moonarch. -->
+<!-- ABOUTME: Loads after 60-latin (number 65) so these prefs win over stock defaults. -->
+<!DOCTYPE fontconfig SYSTEM "urn:fontconfig:fonts.dtd">
+<fontconfig>
+    <description>Moonarch generic-family defaults</description>
+    <!-- binding="strong" required: the default weak <prefer> ranks behind
+         stock generic fallbacks, so it would not take effect. -->
+    <alias binding="strong">
+        <family>sans-serif</family>
+        <prefer>
+            <family>UbuntuSans Nerd Font</family>
+        </prefer>
+    </alias>
+    <alias binding="strong">
+        <family>monospace</family>
+        <prefer>
+            <family>UbuntuSansMono Nerd Font</family>
+        </prefer>
+    </alias>
+</fontconfig>

defaults/xdg/waybar/style.css

@@ -3,7 +3,7 @@
 
 * {
     border: none;
-    font-family: "Ubuntu Nerd Font", sans-serif;
+    font-family: "UbuntuSans Nerd Font", sans-serif;
     font-size: 13px;
     color: alpha(@theme_text_color, 0.8);
 }