Add [tanin] repo build script; build 5 own packages + DB

- packaging/build-tanin-repo.sh: builds own pkgs + repo-add DB (-> ~/projects/tanin-repo)
- built: tanin-greet, tanin-libadwaita, tanin-setup, tanin-eww, tanin-desktop
- manifest: cliphist + cage are in extra (not AUR rebuilds); only eww/tiramisu/
  waypaper need rebuilding into [tanin]; record repo-build status

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

distro/MANIFEST.md

@@ -61,8 +61,7 @@ AUR                                        →  OPT-IN only (paru = optdepend)
 **Rebuilt AUR deps** — the desktop's hard requirements that aren't in the
 official repos. We rebuild them into `[tanin]` so `tanin-desktop` can hard-depend
 on them **without the AUR** (binary repos must never need it): `eww`, `tiramisu`,
-`waypaper`, `cliphist`. ⚠️ Verify each before publishing — any that
-turn out to live in `extra` should be dropped from this list.
+`waypaper`. (`cliphist` + `cage` are in `extra` — pulled from official repos.)
 
 The full Arch package set (compositor, portals, audio, connectivity, fonts, …)
 is enumerated under `[packages.arch]` in `camel.toml` and is the seed for the