fix: bind mounts from DOCKER_PATH + real storage reads from disk

docker-compose.yml:
- Switch from named volumes back to bind mounts driven by DOCKER_PATH in .env
- DOCKER_PATH/config → /config, DOCKER_PATH/data → /data
- Works with both Windows paths (C:\...) and Linux paths (/opt/...)

server.go:
- Wire in storage.Store so documents query reads real .adoc files from disk
- handleDocuments: calls store.List("") and store.Read(slug) for actual content
- extractTitle: parses first "= Title" line from AsciiDoc, falls back to slug
- handleSetup: also initialises store after writing config so docs appear immediately
- Single document query (document(slug:...)) reads and returns full content

.env.example:
- Clarify DOCKER_PATH usage with Windows and Linux examples
- Show resulting directory layout on host

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker/docker-compose.yml

@@ -7,29 +7,23 @@ services:
     container_name: archivum
     restart: unless-stopped
     ports:
-      - "8080:4000"
+      - "${HOST_PORT:-8080}:4000"
 
     environment:
-      # Points to the config directory inside the container.
       DOCKER_PATH: /config
       UI_DIR: /srv/archivum/ui
-      # Set to match the owner of the host directories (run `id` to check).
       PUID: ${PUID:-1000}
       PGID: ${PGID:-1000}
       TZ: ${TZ:-Europe/Stockholm}
 
     volumes:
-      # Configuration (config.json written here by Setup Wizard).
-      - archivum-config:/config
-      # All data: wiki files live in /data/wiki, SQLite db in /data/db.
-      # Using named volumes for local dev avoids Windows/WSL2 permission issues.
-      - archivum-data:/data
-
-# Named volumes let Docker manage ownership automatically.
-# Replace with bind mounts if you need direct host access:
-#   - ./local/config:/config
-#   - ./local/data:/data
-# (and make sure the host directories are owned by PUID:PGID)
-volumes:
-  archivum-config:
-  archivum-data:
+      # DOCKER_PATH in .env is the base directory on the HOST.
+      # Example .env:
+      #   DOCKER_PATH=C:\Repo\AW\Archivum\docker
+      # Results in:
+      #   C:\Repo\AW\Archivum\docker\config  →  /config  (config.json lives here)
+      #   C:\Repo\AW\Archivum\docker\data    →  /data    (wiki/ and db/ live here)
+      #
+      # If DOCKER_PATH is not set, falls back to ./local relative to this file.
+      - ${DOCKER_PATH:-./local}/config:/config
+      - ${DOCKER_PATH:-./local}/data:/data