feat: switch default init from OpenRC to Dinit

All approaches to keep OpenRC as default failed:
  - --ignore: pacman ignores it during fresh install provider resolution
  - --assume-installed=init-logind: ALPM doesn't check assume-installed for virtual providers
  - --ask=12: infinite loop (pacman re-adds elogind-dinit after each removal)
  - dummy package in custom repo: init-rc conflict hits via different path

Dinit works because pacman --noconfirm naturally picks elogind-dinit
(alphabetically before elogind-openrc), pulling dinit-rc which has no
conflict. All inits (OpenRC, Runit, S6) remain selectable in the
online installer.

Changes:
  - buildiso: INITSYS='dinit', remove --assume-installed/--ask hacks
  - basestrap/main.py, packages/main.py: remove same hacks
  - profile.yaml: antergos-live-dinit for dinit, move openrc pkg to init-specific
  - packagechooser.conf (x2): default=Dinit, Dinit first in item list
  - packagechooser_dm.conf: *-dinit instead of *-openrc
  - README.md, README.pl.md, docs/*: update all OpenRC-first references
  - AGENTS.md: document dinit as default

iso-profiles/antergos/live-overlay/usr/lib/calamares/modules/packages/main.py

@@ -221,18 +221,6 @@ class PMPacman(PackageManager):
             command.append("--noprogressbar")
             command.append("--overwrite=*")
 
-            # Pre-tend init-logind is already provided so pacman's resolver
-            # skips provider selection entirely, preventing it from selecting
-            # elogind-dinit (alphabetically before elogind-openrc) which would
-            # pull in dinit -> dinit-rc and conflict with OpenRC.
-            if libcalamares.globalstorage.contains("initProvider"):
-                provider = libcalamares.globalstorage.value("initProvider")
-                if provider and provider != "dinit":
-                    command.append("--assume-installed=init-logind")
-
-            # Safety net: auto-answer YES to conflict resolution
-            command.append("--ask=4")
-
             if self.pacman_needed_only is True:
                 command.append("--needed")
             if self.pacman_disable_timeout is True: