Add compose and attic configurations

Add compose directory to store docker/podman compose files for running
on the TrueNAS box
Add attic configurations to auto-listen on all my home boxes to upload
builds
Update nix-conf to support reading from the Attic server

compose/attic.yaml

@@ -0,0 +1,55 @@
+services:
+  attic:
+    container_name: attic
+    image: ghcr.io/zhaofengli/attic:latest
+    command: ["-f", "/attic/server.toml"]
+    restart: unless-stopped
+    ports:
+      - 8080:8080
+    networks:
+      attic:
+      pgattic:
+    volumes:
+      - /mnt/all/configs/attic/server.toml:/attic/server.toml
+      - /mnt/all/containers/attic/data:/attic/storage
+    env_file:
+      - stack.env
+    depends_on:
+      pgattic:
+        condition: service_healthy
+    healthcheck:
+      test:
+        [
+          "CMD-SHELL",
+          "wget --no-verbose --tries=1 --spider http://attic:8080 || exit 1",
+        ]
+      interval: 15s
+      timeout: 10s
+      retries: 10
+      start_period: 15s
+    deploy:
+      resources:
+        reservations:
+          cpus: 1.0
+
+  pgattic:
+    container_name: pgattic
+    image: postgres:17.6-alpine
+    restart: unless-stopped
+    ports: []
+      #- 5432:5432
+    networks:
+      pgattic:
+    volumes:
+      - /mnt/all/containers/attic/postgres:/var/lib/postgresql/data
+    env_file:
+      - stack.env
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U $${POSTGRES_USER} -d $${POSTGRES_DB}"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+
+networks:
+  attic:
+  pgattic: