packaging/iso: uninstall safety, fail-closed AUR updates, no sshd on live ISO

- tanin-greet.install: post_remove restores the previous greetd config —
  removing the package no longer leaves greetd pointing at a dead binary
- aur-autoupdate: skip packages when the AUR RPC is unreachable instead of
  building blind (fail closed)
- build-tanin-repo: per-package makepkg logs instead of >/dev/null
- live ISO: drop sshd.service enablement (root has an empty password on the
  live medium); encoded in bootstrap-profile.sh so it survives re-bootstrap
- gtklock config: de-personalize hardcoded /home/karim path, mark as
  not-yet-packaged reference
- tanin-desktop PKGBUILD: correct stale AUR-vs-extra comments (gtklock,
  awww, cliphist are in extra), document the eww-git provides=eww contract
- docs/distribution.md: mark SigLevel TrustAll as temporary/insecure, add
  repo-signing TODO (repo-add -s, SigLevel Required), tick done roadmap items
- tanin-calendar + niri-config.kdl: pending session work

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packaging/tanin-eww/niri-config.kdl

@@ -14,11 +14,13 @@ input {
     mouse {}
 }
 
-// Outputs — scale 1.25 like the Hyprland setup. Mode omitted on purpose so niri
-// picks the highest refresh rate automatically (144 Hz on DP-3). Positions are
-// left to niri's auto-placement.
+// Outputs — scale 1.25 like the Hyprland setup. Mode is pinned explicitly:
+// niri's "preferred" mode on DP-3 is only 60 Hz, so omitting it left the
+// monitor at 59.951 Hz. We force the full 143.973 Hz panel rate (gaming).
+// Positions are left to niri's auto-placement.
 output "DP-3" {
     scale 1.25
+    mode "2560x1440@143.973"
 }
 output "HDMI-A-1" {
     scale 1.25
@@ -92,6 +94,18 @@ window-rule {
     clip-to-geometry true
 }
 
+// ---- Gaming: Spiele direkt im echten Vollbild öffnen ----------------------
+// Steam/Proton-Titel (app-id "steam_app_<id>") und gamescope gehen sofort
+// fullscreen auf — ohne Gaps, Rundungen oder geometry-clip (würde sonst die
+// Render-Surface beschneiden). Manuell jederzeit mit Mod+Shift+F umschaltbar.
+window-rule {
+    match app-id="^steam_app_"
+    match app-id="^gamescope$"
+    open-fullscreen true
+    geometry-corner-radius 0
+    clip-to-geometry false
+}
+
 // ---- geblurrtes Wallpaper im Overview-Backdrop ----------------------------
 // Zwei Wallpaper-Surfaces:
 //   * swaybg (namespace "wallpaper")   -> scharf auf dem Desktop (waypaper)