Update flake inputs; drop navidrome; fix noto-fonts subset glob

- Update nixpkgs (Feb 27), home-manager, microvm, nix-index-database,
  claude-code-nix, dailybot
- Remove navidrome service, nginx proxy, dashy entry, and gatus monitor
- Add noto-fonts-subset patch for libreoffice/collabora (noto-fonts
  2026.02.01 switched from variable to static font filenames)
- Add incus-lts writableTmpDirAsHomeHook overlay for sandbox HOME fix
- Add samba4Full overlay to disable CephFS (ceph pinned to python3.11)

.claude/skills/update-flake/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: update-flake
-description: Update nix flake inputs to latest versions, fix build breakage from upstream changes, build all NixOS machines, and run garbage collection. Use when the user wants to update nixpkgs, update flake inputs, upgrade packages, or refresh the flake lockfile.
+description: Update nix flake inputs to latest versions, fix build breakage from upstream changes, and build all NixOS machines. Use when the user wants to update nixpkgs, update flake inputs, upgrade packages, or refresh the flake lockfile.
 ---
 
 # Update Flake
@@ -35,12 +35,6 @@ nix build .#nixosConfigurations.<hostname>.config.system.build.toplevel --no-lin
 
 Fix any build failures before continuing.
 
-### 4. Garbage Collection
-
-```bash
-nix store gc
-```
-
-### 5. Summary
+### 4. Summary
 
 Report: inputs updated, fixes applied, nextcloud changes, and anything needing user attention.