Add README, customization snapshot, and snapshot/restore tooling

Provisioning now restores all GUI customizations on reset+reprovision:

- create_pod_espocrm.sh: deploy the version-controlled espocrm-custom/ tree
  (CTag entity, layouts, i18n, clientDefs, custom views, custom CSS) into the
  pod, then chown www-data and rebuild. Replaces the earlier inline CSS-only
  step. Adds a live-phase cache rebuild so customizations and the client
  cacheTimestamp are refreshed on every run.
- espocrm-custom/: snapshot of custom/ and client/custom/ (source of truth).
- snapshot_espocrm_custom.sh: refresh the snapshot from a running pod.
- readme.md: usage, first-time host setup, image-update and reset workflows.
- Include the task/instruction notes and plan.md for reference.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

snapshot_espocrm_custom.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+# To be run by user mkt. Refreshes the version-controlled GUI-customization
+# snapshot ($CUSTOM_SRC) from the running EspoCRM pod. Run this after making
+# customizations in the EspoCRM GUI (Entity Manager, Layout Manager, Label
+# Manager, etc.) so create_pod_espocrm.sh can restore them on reset+reprovision.
+# Commit the result to the repo afterwards.
+
+# Environment variables
+WEB_CTR='espocrm_ctr'
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+CUSTOM_SRC="$SCRIPT_DIR/espocrm-custom"   # contains custom/ and client/custom/
+
+if ! podman exec "$WEB_CTR" true 2>/dev/null; then
+  echo "ERROR: container $WEB_CTR is not running. Start the pod first." >&2
+  exit 1
+fi
+
+# Pull /var/www/html/{custom,client/custom} into a clean snapshot dir.
+rm -rf "$CUSTOM_SRC"
+mkdir -p "$CUSTOM_SRC"
+podman exec "$WEB_CTR" tar -C /var/www/html -cf - custom client/custom \
+  | tar -C "$CUSTOM_SRC" -xf - --no-same-owner
+echo "Refreshed snapshot at $CUSTOM_SRC (rc=$?)"
+
+echo "Files: $(find "$CUSTOM_SRC" -type f | wc -l)"
+echo "Review and commit, e.g.:  git -C \"$SCRIPT_DIR\" add espocrm-custom && git -C \"$SCRIPT_DIR\" commit -m 'Update EspoCRM customizations snapshot'"