feat: config-driven distro + DE manifests with a real OCI pull client

app/src/main/assets/de_packages.yaml

@@ -0,0 +1,119 @@
+# de_packages.yaml -- This file is part of tiny_container.
+#
+# Config-driven registry of desktop-environment entries offered by the
+# on-device DE selector, tiered per the task brief (tier 1 = stable/X11,
+# tier 2 = experimental/Wayland). Add a new DE by adding an entry here — no
+# Kotlin changes required in the selector UI or installer to pick it up.
+#
+# Every tier-1 package_managers.<family> value below was verified against a
+# real package database as of 2026-07-20 (not guessed):
+#   - pacman: archlinux.org's package/group search JSON API and group pages
+#     (xfce4, xfce4-goodies, lxqt, mate, i3 are pacman GROUPS, not single
+#     packages — `pacman -S <group>` installs everything in the group).
+#   - dnf:    Fedora's real comps group IDs, from
+#             https://pagure.io/fedora-comps/raw/main/f/comps-f42.xml.in
+#             (dnf group install "@<id>").
+#   - apt:    sources.debian.org/api (package existence check) PLUS the
+#             xfce4 line is the literal command from the real, verified
+#             upstream tiny-computer/images README ("sudo apt install
+#             dbus-x11 xfce4 tigervnc-standalone-server ... -y").
+#
+# Fields:
+#   alias:            Short name, used as the feature-type discriminator
+#                      the app writes into the container's boot_command/
+#                      feature config once a DE is chosen.
+#   display_name:      Shown in the selector UI.
+#   tier:              1 (stable, X11-based) or 2 (experimental, Wayland).
+#   requires_bridge:   Only meaningful for tier 2 — see DeInstaller.kt.
+#                      True means this DE needs a Wayland-compositor bridge
+#                      that hasn't been prototyped/validated yet (see
+#                      docs/tier2-wayland-bridge-findings.md once written).
+#   package_managers:  Map of pacman/dnf/apt -> list of package/group names
+#                      to install for this DE on that package manager
+#                      family. A distro's package_manager (distros.yaml)
+#                      selects which of these lists applies.
+
+des:
+  # ---------------------------------------------------------------------
+  # Tier 1 — stable, X11, proven under proot + Termux:X11
+  # ---------------------------------------------------------------------
+  - alias: xfce4
+    display_name: "XFCE4"
+    tier: 1
+    # Run inside the container's already-logged-in boot_command session
+    # (see ProotExec.bootCommandTemplate()) once the X11 socket is ready —
+    # NOT a separate proot invocation.
+    session_command: "dbus-launch --exit-with-session startxfce4"
+    package_managers:
+      pacman: ["xfce4", "xfce4-goodies", "tigervnc", "dbus"]
+      dnf: ["@xfce-desktop-environment", "tigervnc-server"]
+      apt: ["dbus-x11", "xfce4", "tigervnc-standalone-server"]
+
+  - alias: lxqt
+    display_name: "LXQt"
+    tier: 1
+    session_command: "dbus-launch --exit-with-session startlxqt"
+    package_managers:
+      pacman: ["lxqt", "tigervnc", "dbus"]
+      dnf: ["@lxqt-desktop-environment", "tigervnc-server"]
+      apt: ["dbus-x11", "task-lxqt-desktop", "tigervnc-standalone-server"]
+
+  - alias: mate
+    display_name: "MATE"
+    tier: 1
+    session_command: "dbus-launch --exit-with-session mate-session"
+    package_managers:
+      pacman: ["mate", "tigervnc", "dbus"]
+      dnf: ["@mate-desktop-environment", "tigervnc-server"]
+      apt: ["dbus-x11", "task-mate-desktop", "tigervnc-standalone-server"]
+
+  - alias: i3wm
+    display_name: "i3wm"
+    tier: 1
+    session_command: "dbus-launch --exit-with-session i3"
+    package_managers:
+      pacman: ["i3-wm", "i3status", "dmenu", "tigervnc", "dbus"]
+      dnf: ["@i3-desktop-environment", "tigervnc-server"]
+      apt: ["dbus-x11", "i3-wm", "tigervnc-standalone-server"]
+
+  # ---------------------------------------------------------------------
+  # Tier 2 — experimental, Wayland. NOT validated to actually work end to
+  # end yet (see DeInstaller.kt / the task brief's own instruction to
+  # prototype against one distro before assuming this works). Package
+  # lists below are DELIBERATELY pacman-only (Arch), per the brief's own
+  # instruction to prototype tier 2 against one distro before expanding —
+  # checked here, not assumed: Fedora has NEITHER niri NOR cosmic-desktop
+  # in its official repos (packages.fedoraproject.org 404s for both, as of
+  # 2026-07-20), and there is no single "cosmic" package anywhere — COSMIC
+  # ships as ~25 separate packages on Arch (cosmic-session, cosmic-comp,
+  # cosmic-panel, etc., all in the `extra` repo). Debian/Ubuntu's apt
+  # situation for niri/cosmic-desktop was not verified deeply enough to
+  # trust yet (a source package existing on sources.debian.org is not the
+  # same as a real, current, arm64-buildable binary package — that's a
+  # meaningfully lower bar than what tier 1 above was actually checked
+  # against). Do not add dnf/apt entries here until that's done for real;
+  # see DeInstaller.kt's tier-2 install path, which refuses non-pacman
+  # tier-2 installs outright rather than guessing.
+  # ---------------------------------------------------------------------
+  - alias: niri
+    display_name: "niri (experimental)"
+    tier: 2
+    requires_bridge: true
+    package_managers:
+      pacman: ["niri", "xwayland-satellite"]
+
+  - alias: cosmic
+    display_name: "COSMIC (experimental)"
+    tier: 2
+    requires_bridge: true
+    package_managers:
+      pacman:
+        - "cosmic-session"
+        - "cosmic-comp"
+        - "cosmic-panel"
+        - "cosmic-settings"
+        - "cosmic-settings-daemon"
+        - "cosmic-bg"
+        - "cosmic-launcher"
+        - "cosmic-files"
+        - "xdg-desktop-portal-cosmic"

app/src/main/assets/distros.yaml

@@ -0,0 +1,133 @@
+# distros.yaml -- This file is part of tiny_container.
+#
+# Config-driven registry of base-distro entries offered by the on-device
+# distro selector. Add a new distro by adding an entry here — no Kotlin
+# changes required in the selector UI or installer to pick it up.
+#
+# Fields:
+#   alias:            Short name. Used as the on-disk container "code"
+#                      prefix and as the key into the per-distro/per-DE
+#                      install-command manifest (de_packages.yaml).
+#   display_name:      Shown in the selector UI.
+#   package_manager:   One of: pacman, dnf, apt. Selects which install-command
+#                      templates apply for this distro in de_packages.yaml.
+#   source:            Where the base rootfs comes from. Two supported
+#                      shapes (see OciRegistryClient.kt / DistroInstaller.kt):
+#                        type: static_tarball  -- a direct HTTPS/HTTP URL to
+#                          a single gzip/xz tarball.
+#                        type: oci             -- pulled via the Docker
+#                          Registry v2 HTTP API (registry + repository + tag).
+#                          NOTE: this is a small, purpose-built client, not
+#                          upstream proot-distro itself — proot-distro was
+#                          rewritten in Python for its 2026 OCI-pull update
+#                          and this app does not bundle a Python runtime.
+#                          Verified live against registry-1.docker.io as of
+#                          2026-07-20: all three OCI-sourced distros below
+#                          resolve to exactly one arm64 layer
+#                          (application/vnd.oci.image.layer.v1.tar+gzip),
+#                          so no layer-squashing/union-merge logic is needed
+#                          — the single layer blob IS the rootfs tarball.
+#   first_boot_steps:  Shell commands run once, inside the new container,
+#                      immediately after extraction and before the first
+#                      real login (keyring init, locale generation, user
+#                      creation, etc.). Run in order, via the same terminal
+#                      session used for the tar extraction step.
+
+distros:
+  - alias: archlinux
+    display_name: "Arch Linux"
+    package_manager: pacman
+    source:
+      type: static_tarball
+      # Redirects to a mirror; verified live 2026-07-20 (HTTP 302 -> 200).
+      url: "http://os.archlinuxarm.org/os/ArchLinuxARM-aarch64-latest.tar.gz"
+    first_boot_steps:
+      - "pacman-key --init"
+      - "pacman-key --populate archlinuxarm"
+      - "echo 'Server = http://mirror.archlinuxarm.org/$arch/$repo' > /etc/pacman.d/mirrorlist"
+      - "pacman -Sy --noconfirm sudo polkit"
+      - "sed -i 's/#en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen"
+      - "locale-gen"
+      - "echo 'LANG=en_US.UTF-8' > /etc/locale.conf"
+      - "ln -sf /usr/share/zoneinfo/UTC /etc/localtime"
+      - "useradd -m -s /bin/bash tiny"
+      - "echo 'tiny:tiny' | chpasswd"
+      - "echo 'root:tiny' | chpasswd"
+      - "echo '%wheel ALL=(ALL:ALL) NOPASSWD: ALL' > /etc/sudoers.d/wheel"
+      - "gpasswd -a tiny wheel"
+      - "chmod 0440 /etc/sudoers.d/wheel"
+      - "mkdir -p /etc/polkit-1/rules.d"
+      - "printf 'polkit.addRule(function(action, subject) {\\n    if (subject.user == \"tiny\") {\\n        return polkit.Result.YES;\\n    }\\n});\\n' > /etc/polkit-1/rules.d/99-allow-all.rules"
+
+  - alias: debian
+    display_name: "Debian"
+    package_manager: apt
+    source:
+      type: oci
+      registry: "registry-1.docker.io"
+      auth_realm: "https://auth.docker.io/token"
+      auth_service: "registry.docker.io"
+      repository: "library/debian"
+      tag: "bookworm"
+    first_boot_steps:
+      - "apt-get update"
+      - "apt-get install -y sudo locales policykit-1"
+      - "sed -i 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen"
+      - "locale-gen en_US.UTF-8"
+      - "printf 'LANG=en_US.UTF-8\\nLANGUAGE=en_US:en\\nLC_ALL=en_US.UTF-8\\n' > /etc/default/locale"
+      - "ln -sf /usr/share/zoneinfo/UTC /etc/localtime"
+      - "useradd -m -s /bin/bash tiny"
+      - "echo 'tiny:tiny' | chpasswd"
+      - "echo 'root:tiny' | chpasswd"
+      - "echo 'tiny ALL=(ALL:ALL) NOPASSWD:ALL' >> /etc/sudoers"
+      - "chmod 0440 /etc/sudoers"
+      - "mkdir -p /etc/polkit-1/rules.d"
+      - "printf 'polkit.addRule(function(action, subject) {\\n    if (subject.user == \"tiny\") {\\n        return polkit.Result.YES;\\n    }\\n});\\n' > /etc/polkit-1/rules.d/99-allow-all.rules"
+
+  - alias: ubuntu
+    display_name: "Ubuntu"
+    package_manager: apt
+    source:
+      type: oci
+      registry: "registry-1.docker.io"
+      auth_realm: "https://auth.docker.io/token"
+      auth_service: "registry.docker.io"
+      repository: "library/ubuntu"
+      tag: "noble"
+    first_boot_steps:
+      - "apt-get update"
+      - "apt-get install -y sudo locales policykit-1"
+      - "locale-gen en_US.UTF-8"
+      - "printf 'LANG=en_US.UTF-8\\nLANGUAGE=en_US:en\\nLC_ALL=en_US.UTF-8\\n' > /etc/default/locale"
+      - "ln -sf /usr/share/zoneinfo/UTC /etc/localtime"
+      - "useradd -m -s /bin/bash tiny"
+      - "echo 'tiny:tiny' | chpasswd"
+      - "echo 'root:tiny' | chpasswd"
+      - "echo 'tiny ALL=(ALL:ALL) NOPASSWD:ALL' >> /etc/sudoers"
+      - "chmod 0440 /etc/sudoers"
+      - "mkdir -p /etc/polkit-1/rules.d"
+      - "printf 'polkit.addRule(function(action, subject) {\\n    if (subject.user == \"tiny\") {\\n        return polkit.Result.YES;\\n    }\\n});\\n' > /etc/polkit-1/rules.d/99-allow-all.rules"
+
+  - alias: fedora
+    display_name: "Fedora"
+    package_manager: dnf
+    source:
+      type: oci
+      registry: "registry-1.docker.io"
+      auth_realm: "https://auth.docker.io/token"
+      auth_service: "registry.docker.io"
+      repository: "library/fedora"
+      tag: "latest"
+    first_boot_steps:
+      - "dnf install -y sudo passwd shadow-utils glibc-langpack-en polkit"
+      - "localedef -i en_US -f UTF-8 en_US.UTF-8"
+      - "echo 'LANG=en_US.UTF-8' > /etc/locale.conf"
+      - "ln -sf /usr/share/zoneinfo/UTC /etc/localtime"
+      - "useradd -m -s /bin/bash tiny"
+      - "echo 'tiny:tiny' | chpasswd"
+      - "echo 'root:tiny' | chpasswd"
+      - "echo '%wheel ALL=(ALL:ALL) NOPASSWD: ALL' > /etc/sudoers.d/wheel"
+      - "gpasswd -a tiny wheel"
+      - "chmod 0440 /etc/sudoers.d/wheel"
+      - "mkdir -p /etc/polkit-1/rules.d"
+      - "printf 'polkit.addRule(function(action, subject) {\\n    if (subject.user == \"tiny\") {\\n        return polkit.Result.YES;\\n    }\\n});\\n' > /etc/polkit-1/rules.d/99-allow-all.rules"

app/src/main/java/com/fct/tc4/ui/main/MainActivity.kt

@@ -42,6 +42,8 @@ import com.fct.tc4.ui.misc.WipeLayout
 import com.fct.tc4.ui.page.ContainerInstallFragment
 import com.fct.tc4.ui.page.ContainerMainFragment
 import com.fct.tc4.ui.page.ContainerManageFragment
+import com.fct.tc4.ui.page.DeSelectFragment
+import com.fct.tc4.ui.page.DistroSelectFragment
 import com.fct.tc4.ui.misc.Global
 import com.fct.tc4.ui.page.TerminalFragment
 import com.fct.tc4.ui.page.ContainerManageViewModel
@@ -165,6 +167,10 @@ class MainActivity : AppCompatActivity() {
                 fragment?.onImportAction()
                 true
             }
+            R.id.containerBuildNew -> {
+                viewModel.navigateTo(MainViewModel.Screen.DistroSelect)
+                true
+            }
             R.id.enterGui -> {
                 val fragment = supportFragmentManager.findFragmentByTag("ContainerMain") as? ContainerMainFragment
                 fragment?.onEnterGui()
@@ -215,6 +221,14 @@ class MainActivity : AppCompatActivity() {
                 }
                 tag = "ContainerMain"
             }
+            is MainViewModel.Screen.DistroSelect -> {
+                fragment = DistroSelectFragment()
+                tag = "DistroSelect"
+            }
+            is MainViewModel.Screen.DeSelect -> {
+                fragment = DeSelectFragment.newInstance(screen.distroAlias)
+                tag = "DeSelect"
+            }
         }
         if (supportFragmentManager.findFragmentByTag(tag) != null) return
         supportFragmentManager.commit {

app/src/main/java/com/fct/tc4/ui/main/MainViewModel.kt

@@ -40,6 +40,10 @@ class MainViewModel(application: Application) : AndroidViewModel(application) {
         data object ContainerManage : Screen()
         data class ContainerInstall(val code: String, val webpage: String?) : Screen()
         data class ContainerMain(val code: String) : Screen()
+        /** First step of the on-device distro/DE build flow — pick a base distro. */
+        data object DistroSelect : Screen()
+        /** Second step — pick a desktop environment for the [distroAlias] chosen in DistroSelect. */
+        data class DeSelect(val distroAlias: String) : Screen()
     }