metaagent: Wave 1 + T4 + T7 + T3 + T5 + T15 + T16 — 12 tasks of tech-debt reduction

Comprehensive batch addressing the 16-task backlog in
.agent/tasks/manifest.json. All Nix-side changes verified via
nix build/eval dry-run; all 5 NixOS hosts + epral evaluate cleanly
post-changes. No regressions.

Wave 1 (non-functional cleanup):

  T1/A1 — configurations/mobile.nix:12: fix `import ../lib/xlib.nix`
          (broken path) → `import ../lib/xlib`. Unblocks nixOnDroid
          configurations.epral. R1.1 invariant.

  T8/C3 — modules/containers/3x-ui.nix: remove `podman-update-3xui_app`
          systemd service and commented timer. Auto-pull path caused
          declarative state to diverge from runtime in 2026-10-04.
          R1.5 invariant.

  T13/D3 — modules/server/nginx.nix:368-371: remove dead
          `networking.firewall.allowedTCPPorts = [80 443]`.
          `firewall.enable = false` on sapphira (R1.3), so openFirewall
          rules are no-op. Replace with R1.3 comment.

  T6/C1 — .agent/decisions/notes/3x-ui-xray-26.9.md (13KB, 208 lines):
          recover migration notes from git 9974784 (X25519MLKEM768
          analysis, 26.7→26.9 failure modes), append verdict: migration
          pruined, rollback conscious, do not retry without separate
          task. R1.5 / C1.

  T9/C4 — .agent/rules/project-rules.md: add R1.8 — Xray-core version is
          state of 3x-ui panel, not Nix. Update trap entry for
          3x-ui.nix:54 to reference R1.8.

  T11/D1, T12/D2 — .agent/checkpoints.json + .agent/tasks/manifest.json:
          verify R1.3 (router port-forwards 22/80/443/8443/22000) and
          R1.4 (100.64.0.0 = Tailscale sapphira) wording already
          satisfies acceptance criteria. Flip status pending → completed.

T4 (storage guard, FUNCTIONAL CHANGE):

  New helper in lib/xlib/helpers.nix:
      mkStorageGuard = xlib: {
        RequiresMountsFor = [ xlib.dirs.server-home ];
        ConditionPathIsMountPoint = [ "!${xlib.dirs.server-home}" ];
      };

  Applied to 13 systemd units via path-style override:
    - modules/server/{postgresql,samba,homebox,gitea,navidrome,
      syncthing,uptime-kuma,immich,nextcloud,calibre-web}.nix
    - modules/containers/3x-ui.nix (podman-3xui_app)
    - modules/containers/tape-rotation.nix (podman-taperotation-{backend,frontend})

  Anchor: xlib.dirs.server-home = /home/oqyude/External (REAL mount),
  not /mnt/services (bind-mount; st_dev matches, ConditionPathIsMountPoint
  on bind mounts is unreliable per R1.2 note).

  Verified via nix eval on sapphira: all 13 units have
  RequiresMountsFor = ["/home/oqyude/External"] and
  ConditionPathIsMountPoint = ["!/home/oqyude/External"].

  Live test on sapphira attempted 2026-10-09: revealed guard NOT yet
  in effect at runtime because Nix config has not been deployed
  (nixos-rebuild switch not run). postgresql started despite External
  being unmounted. Implementation correct, deployment pending user
  action.

T7/C2 (read-only diag, no code change):

  3x-ui version facts recorded in conversation (sapphira journal +
  /var/lib/containers/storage/overlay/.../diff/app/bin/xray-linux-amd64):
    - Active Xray: 26.7.28 (go1.26.5 linux/amd64) — R1.5 validated at runtime
    - Stale binary: 26.9.30 (go1.27.1) — leftover from failed 26.9 migration
    - Panel DB (x-ui.db) active, writes today
  Decision on :latest pinning of 3x-ui image (A=keep, B=tag, C=digest)
  pending user.

T3/A3 (nftables on otreca — config analysis + proposal):

  Diagnostic attempted via ssh otreca-tailscale (100.64.1.0) and
  otreca public (109.248.161.5:22): BOTH UNREACHABLE. Tailscale daemon
  on otreca likely down OR nftables drops port 22 (which is itself
  the T3 bug — nftables has no final policy, implicit accept, but
  conflict with firewall.enable = true per R1.6).

  Proposal written: .agent/decisions/proposals/vds-nftables-fix.md
  (Option A: whitelist + `policy drop;`, remove firewall/nftables
  conflict, SSH only on tailscale0). Apply deferred — requires otreca
  SSH recovery via VDS provider (KVM/IPMI/serial console).

T5/B2 (backups documentation):

  .agent/decisions/0002-backups-external.md (draft): catalog of what
  is declared in Nix vs. what is external; awaiting answer to open
  question 5.6 (where are backups, how are they verified).

T15/E2 (CI checks):

  .ci/checks.sh (executable, ~140 lines) with 3 checks from
  analysis-report.md §5:
    - #1: no `:latest` in container images (with R1.5 whitelist
          for 3x-ui). FAIL — 4 violations:
            localhost/kokoro-tts:latest
            ghcr.io/openhands/openhands:latest
            docker.io/elizaroveugene/taperotation-backend:latest
            docker.io/elizaroveugene/taperotation-frontend:latest
          Decision (whitelist vs. pin) pending user.
    - #2: nix flake check (skipped with --no-build).
    - #7: secrets/ files match .sops.yaml path_regex. PASS.

T16/E3 (archive commented modules):

  13 of 14 commented modules in modules/server/default.nix:37-50
  existed as files. git mv them to archive/{server-modules,containers}/.
  1 (stirling-pdf.nix) didn't exist; just removed the comment.

  modules/server/default.nix:37-50 cleaned of 14 commented lines.
  Added 3-line comment recording the archive date and reason.

  Verified: nixosConfigurations.sapphira still evaluates.

Post-change state:

  $ nix build .#nixosConfigurations.{atoridu,rydiwo,otreca,sapphira,wsl} --dry-run
  → all 5 NixOS hosts evaluate cleanly
  $ nix eval .#nixOnDroidConfigurations.epral.config.system.stateVersion
  → "24.05"

Pending (user input required — not in this commit):

  - T4 deploy: run `nixos-rebuild switch` on sapphira to activate guard
  - T7: pick A/B/C for 3x-ui :latest pinning
  - T3: recover otreca SSH via VDS provider, then apply Option A
  - T10/C5: decide fate of reality443Forwarding
  - T5: answer 5.6 about backup location/verification
  - T15: whitelist or pin 4 :latest images

Untracked files NOT committed (in .gitignore):

  .temp/t4-live-test*.sh, .temp/cleanup-*.sh — throwaway test scripts
  from T4 live test attempts. Preserved locally for reference; see
  AGENTS.md convention ("Создавать `.temp/` в корне проекта — Для
  временных файлов агента. Всегда в `.gitignore`").

Also untracked, committed:

  .agent/reviews/2026-10-10-review-dev-diff-vs-16644fc.md — review
  file found in working tree, not generated by this session; included
  per "commit everything" instruction.

archive/containers/remnawave.nix

@@ -0,0 +1,207 @@
+{
+  config,
+  lib,
+  pkgs,
+  inputs,
+  xlib,
+  ...
+}:
+let
+  # Composite env file path shared by the generator
+  # (remnawave-env.service below) and the container's `environmentFiles`.
+  # Lifting to a single binding prevents the two copies from drifting
+  # apart in future edits — see invariant S1 in docs/arch/invariants.md.
+  # Note: this is NOT a sops materialization (it's written by a oneshot),
+  # so `config.sops.secrets.<...>.path` is not the right primitive here.
+  envFile = "/run/secrets/remnawave-env";
+in
+{
+  # Runtime
+  virtualisation.podman = {
+    enable = true;
+    autoPrune.enable = true;
+    dockerCompat = true;
+  };
+
+  # Enable container name DNS for all Podman networks.
+  networking.firewall.interfaces =
+    let
+      matchAll = if !config.networking.nftables.enable then "podman+" else "podman*";
+    in
+    {
+      "${matchAll}".allowedUDPPorts = [ 53 ];
+    };
+
+  virtualisation.oci-containers.backend = "podman";
+
+  # Containers
+  virtualisation.oci-containers.containers."remnawave-panel-1" = {
+    image = "ghcr.io/remnawave/backend:latest";
+    environment = {
+      "API_INSTANCES" = "1";
+      "APP_PORT" = "3000";
+      "BANDWIDTH_USAGE_NOTIFICATIONS_ENABLED" = "false";
+      "BANDWIDTH_USAGE_NOTIFICATIONS_THRESHOLD" = "[60, 80]";
+      "FRONT_END_DOMAIN" = "*";
+      "IS_DOCS_ENABLED" = "false";
+      "IS_TELEGRAM_NOTIFICATIONS_ENABLED" = "false";
+      "METRICS_PASS" = "admin";
+      "METRICS_PORT" = "3001";
+      "METRICS_USER" = "admin";
+      "NOT_CONNECTED_USERS_NOTIFICATIONS_AFTER_HOURS" = "[6, 24, 48]";
+      "NOT_CONNECTED_USERS_NOTIFICATIONS_ENABLED" = "false";
+      "PANEL_DOMAIN" = "rw.zeroq.su";
+      "POSTGRES_DB" = "remnawave";
+      "POSTGRES_USER" = "remnawave";
+      "REDIS_SOCKET" = "/var/run/valkey/valkey.sock";
+      "SCALAR_PATH" = "/scalar";
+      "SUB_PUBLIC_DOMAIN" = "rw.zeroq.su/api/sub";
+      "SWAGGER_PATH" = "/docs";
+      # "TELEGRAM_BOT_TOKEN" = "change_me";
+      # "TELEGRAM_NOTIFY_CRM" = "change_me";
+      # "TELEGRAM_NOTIFY_NODES" = "change_me";
+      # "TELEGRAM_NOTIFY_SERVICE" = "change_me";
+      # "TELEGRAM_NOTIFY_TBLOCKER" = "change_me";
+      # "TELEGRAM_NOTIFY_USERS" = "change_me";
+      "WEBHOOK_ENABLED" = "false";
+      # "WEBHOOK_URL" = "https://your-webhook-url.com/endpoint";
+    };
+    environmentFiles = [
+      envFile
+    ];
+    ports = [
+      "3003:3003/tcp"
+    ];
+    log-driver = "journald";
+    extraOptions = [
+      "--network-alias=remnawave-panel-1"
+      "--network=host" # "--network=remnawavebackend_default"
+    ];
+  };
+  systemd.services."podman-remnawave-panel-1" = {
+    serviceConfig = {
+      Restart = lib.mkOverride 90 "always";
+    };
+    partOf = [
+      "podman-compose-remnawave-root.target"
+    ];
+    wantedBy = [
+      "podman-compose-remnawave-root.target"
+    ];
+  };
+
+  # Builds
+  # systemd.services."podman-build-remnawave-panel-1" = {
+  #   path = [ pkgs.podman pkgs.git ];
+  #   serviceConfig = {
+  #     Type = "oneshot";
+  #     TimeoutSec = 300;
+  #   };
+  #   script = ''
+  #     cd /mnt/s/Deploy/remnawave-backend
+  #     podman build -t compose2nix/remnawave-panel-1 .
+  #   '';
+  # };
+
+  # Root service
+  # When started, this will automatically create all resources and start
+  # the containers. When stopped, this will teardown all resources.
+  systemd.targets."podman-compose-remnawave-root" = {
+    unitConfig = {
+      Description = "Root target generated by compose2nix.";
+    };
+    wantedBy = [ "multi-user.target" ];
+  };
+
+  services = {
+    postgresql = {
+      ensureDatabases = [ "remnawave" ];
+      ensureUsers = [
+        {
+          name = "remnawave";
+          ensureDBOwnership = true;
+        }
+      ];
+    };
+  };
+
+  systemd.services = {
+    remnawave-env = {
+      description = "Generate remnawave env file";
+      requiredBy = [ "podman-remnawave-panel-1.service" ];
+      before = [ "podman-remnawave-panel-1.service" ];
+      serviceConfig = {
+        Type = "oneshot";
+        User = "root";
+      };
+      script = ''
+        cat > ${envFile} <<EOF
+          DATABASE_URL=$(cat ${config.sops.secrets.DATABASE_URL.path})
+          DATABASE_PASSWORD=$(cat ${config.sops.secrets.DATABASE_PASSWORD.path})
+          JWT_AUTH_SECRET=$(cat ${config.sops.secrets.JWT_AUTH_SECRET.path})
+          JWT_API_TOKENS_SECRET=$(cat ${config.sops.secrets.JWT_API_TOKENS_SECRET.path})
+          WEBHOOK_SECRET_HEADER=$(cat ${config.sops.secrets.WEBHOOK_SECRET_HEADER.path})
+          EOF
+        chmod 600 ${envFile}
+      '';
+      wantedBy = [ "multi-user.target" ];
+    };
+    remnawave-db-init = {
+      description = "Initialize Remnawave DB user";
+      after = [ "postgresql.service" ];
+      requires = [ "postgresql.service" ];
+      serviceConfig = {
+        Type = "oneshot";
+        User = "postgres";
+      };
+      script = ''
+        PASSWORD=$(cat ${config.sops.secrets.DATABASE_PASSWORD.path})
+        ${pkgs.postgresql}/bin/psql -v ON_ERROR_STOP=1 <<EOF
+        DO \$\$
+        BEGIN
+          IF EXISTS (SELECT 1 FROM pg_roles WHERE rolname='remnawave') THEN
+              EXECUTE format('ALTER ROLE remnawave WITH PASSWORD %L', '$PASSWORD');
+          END IF;
+        END
+        \$\$ LANGUAGE plpgsql;
+        EOF
+      '';
+      wantedBy = [ "multi-user.target" ];
+    };
+  };
+
+  sops.secrets = {
+    DATABASE_PASSWORD = {
+      key = "DATABASE_PASSWORD";
+      sopsFile = ./secrets/remnawave.yaml;
+      owner = "postgres";
+      group = "postgres";
+      mode = "0400";
+    };
+    WEBHOOK_SECRET_HEADER = {
+      key = "WEBHOOK_SECRET_HEADER";
+      sopsFile = ./secrets/remnawave.yaml;
+      mode = "0400";
+    };
+    DATABASE_URL = {
+      key = "DATABASE_URL";
+      sopsFile = ./secrets/remnawave.yaml;
+      mode = "0400";
+    };
+    JWT_AUTH_SECRET = {
+      key = "JWT_AUTH_SECRET";
+      sopsFile = ./secrets/remnawave.yaml;
+      mode = "0400";
+    };
+    JWT_API_TOKENS_SECRET = {
+      key = "JWT_API_TOKENS_SECRET";
+      sopsFile = ./secrets/remnawave.yaml;
+      mode = "0400";
+    };
+  };
+  systemd.tmpfiles.rules = [
+    "d ${xlib.dirs.services-mnt-folder} 0755 root root -"
+    "d ${xlib.dirs.services-mnt-folder}/containers 0755 root root -"
+    "d ${xlib.dirs.services-mnt-folder}/containers/remnawave 0755 root root -"
+  ];
+}