fix: config.json lives in data dir, not bind-mounted as file

Removes the separate config.json file bind mount from both compose
files. The data directory mount already covers it, and the Go server
searches /app/data/config.json via LoadConfig.

- Entrypoint symlinks /app/data/config.json for ingestor compatibility
- manage.sh setup creates config in data dir, prompts admin if missing
- manage.sh start checks config exists before starting, offers to create
- deploy.yml simplified — no more sudo rm or directory cleanup
- Backup/restore updated to use data dir path

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

docker/entrypoint-go.sh

@@ -1,16 +1,12 @@
 #!/bin/sh
 
-# Fix: Docker creates a directory when bind-mounting a non-existent file.
-# If config.json is a directory (from a failed mount), remove it and use the example.
-if [ -d /app/config.json ]; then
-  echo "[entrypoint] WARNING: config.json is a directory (broken bind mount) — removing and using example"
-  rm -rf /app/config.json
-fi
-
-# Copy example config if no config.json exists (not bind-mounted)
-if [ ! -f /app/config.json ]; then
-  echo "[entrypoint] No config.json found, copying from config.example.json"
-  cp /app/config.example.json /app/config.json
+# Config lives in the data directory (bind-mounted from host)
+# The Go server already searches /app/data/config.json via LoadConfig
+# but the ingestor expects a direct path — symlink for compatibility
+if [ -f /app/data/config.json ]; then
+  ln -sf /app/data/config.json /app/config.json
+elif [ ! -f /app/config.json ]; then
+  echo "[entrypoint] No config.json found in /app/data/ — using built-in defaults"
 fi
 
 # theme.json: check data/ volume (admin-editable on host)