fix(manage): migrate legacy config path during start/update (#316)

## Summary
- simplified `migrate_config` in `manage.sh` to only migrate legacy
`./config.json` into `${PROD_DATA}/config.json`
- removed the custom destination-path prompt to avoid suggesting
unsupported runtime paths
- added mode-aware behavior:
  - `cmd_start` calls `migrate_config "$PROD_DATA"` (interactive prompt)
- `cmd_update` calls `migrate_config "$PROD_DATA" auto` (non-interactive
auto-migration)
- improved interactive migration copy with explicit source/destination
and runtime note
- when migration is declined from `cmd_start`, script aborts with clear
instructions

## Behavior details
- If `${PROD_DATA}/config.json` exists: no-op
- If only `./config.json` exists:
  - `cmd_start` shows:
    - `Source: ./config.json (repo root)`
    - `Destination: ${PROD_DATA}/config.json`
    - `Note: CoreScope reads config from the data directory at runtime.`
  - prompt: `Move to ${PROD_DATA}/config.json? [Y/n]`
  - yes/default: copies to `${PROD_DATA}/config.json`
  - no: aborts with guidance to move the file and rerun
  - `cmd_update`: auto-copies with:
- `→ Migrating config.json from repo root to
${PROD_DATA}/config.json...`
    - `✓ Config migrated.`
- If neither exists: existing `ensure_config` fallback remains in place

## Validation performed
- ✅ Target exists (`${PROD_DATA}/config.json`) → no-op
- ✅ Legacy exists (`./config.json`), `cmd_start` → prompts, copies on
yes
- ✅ Legacy exists (`./config.json`), `cmd_update` → auto-copies without
prompt
- ✅ Both missing → `ensure_config` fallback flow still handles config
creation/abort path
- ✅ `bash -n manage.sh` passes

## Tests run
- `bash -n manage.sh`
- `node test-packet-filter.js`
- `node test-aging.js`
- `node test-frontend-helpers.js`
- `go test ./...` in `cmd/server`
- `go test ./...` in `cmd/ingestor`

---------

Co-authored-by: Kpa-clawbot <259247574+Kpa-clawbot@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

manage.sh

@@ -916,6 +916,48 @@ container_health() {
 
 # ─── Start / Stop / Restart ──────────────────────────────────────────────
 
+# Migrate legacy root config.json to data directory path
+migrate_config() {
+  local mode="${1:-interactive}"
+  local legacy_config="./config.json"
+  local target_config="$PROD_DATA/config.json"
+  local reply=""
+
+  mkdir -p "$PROD_DATA"
+
+  if [ -f "$target_config" ]; then
+    return 0
+  fi
+
+  if [ ! -f "$legacy_config" ]; then
+    return 0
+  fi
+
+  if [ "$mode" = "auto" ]; then
+    echo "→ Migrating config.json from repo root to ${PROD_DATA}/config.json..."
+    cp "$legacy_config" "$target_config"
+    echo "✓ Config migrated."
+    return 0
+  fi
+
+  echo ""
+  echo "Found legacy config location:"
+  echo "  Source: ./config.json (repo root)"
+  echo "  Destination: ${PROD_DATA}/config.json"
+  echo "  Note: CoreScope reads config from the data directory at runtime."
+  read -p "Move to ${PROD_DATA}/config.json? [Y/n] " reply
+
+  if [ -z "$reply" ] || [[ "$reply" =~ ^[Yy]$ ]]; then
+    cp "$legacy_config" "$target_config"
+    log "Copied config.json to ${target_config}"
+    return 0
+  fi
+
+  warn "Migration aborted."
+  echo "Move ./config.json to ${PROD_DATA}/config.json, then run this command again."
+  return 1
+}
+
 # Ensure config.json exists in the data directory before starting
 ensure_config() {
   local data_dir="$1"
@@ -986,6 +1028,7 @@ cmd_start() {
     fi
   fi
 
+  migrate_config || exit 1
   # Always check prod config
   ensure_config "$PROD_DATA"
 
@@ -1254,6 +1297,8 @@ cmd_update() {
   info "Pulling latest code..."
   git pull --ff-only
 
+  migrate_config auto
+
   info "Rebuilding image..."
   dc_prod build prod