Restructure repo (#251)

* refactor: restructure src/ into modules/, scripts/, and build/

- src/nag_screen/ and src/node_info/ -> src/modules/  (mods grouped explicitly)
- src/Scripts/ -> src/scripts/                        (lowercase, consistent)
- src/gen-rules.sh -> build/                          (build tool separated from source)

Update all references: debian/rules, .github/workflows/*, build/gen-rules.sh,
src/scripts/test/test-syntax.sh (SRC_DIR now points to src/modules/),
src/scripts/test/test-patches.sh, and files.list comments.

* refactor: move CI test scripts from src/scripts/test/ to build/test/

Test scripts are not installed — they are CI/dev tooling and belong
alongside build/gen-rules.sh. Update workflow references and fix the
SRC_DIR path depth in build/test/test-syntax.sh (../ -> ../..).

* d

---------

Co-authored-by: Meliox <na>

src/modules/node_info/patches/post-apply.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+# post-apply hook for the node_info mod.
+# Runs after node_info patches are applied. Provided env: MOD_CONF, STASH_DIR,
+# CONFD_DIR. Creates the GPU RRD storage directory when GPU history is enabled.
+# Exit codes: 0 = no change, 100 = changed (restart pveproxy), other = error.
+
+set -u
+
+GPU_RRD_DIR="/var/lib/rrdcached/db/pve-mod-gpu"
+
+read_conf() {
+    local file="$1" section="$2" key="$3" default="${4:-0}"
+    [[ -f "$file" ]] || { echo "$default"; return; }
+    local val
+    val=$(awk -F= -v sec="[$section]" -v k="$key" '
+        /^\[/ { in_sec = ($0 == sec) }
+        in_sec && /^[^#=]+=/ {
+            gsub(/^[[:space:]]+|[[:space:]]+$/, "", $1)
+            if ($1 == k) { gsub(/^[[:space:]]+|[[:space:]]+$/, "", $2); print $2; exit }
+        }
+    ' "$file")
+    echo "${val:-$default}"
+}
+
+gpu_history="$(read_conf "${MOD_CONF:-/etc/pve-mod/conf.d/node_info.conf}" gpu gpu_history 0)"
+
+if [[ "$gpu_history" == "1" && ! -d "$GPU_RRD_DIR" ]]; then
+    mkdir -p "$GPU_RRD_DIR"
+    chown www-data:www-data "$GPU_RRD_DIR" 2>/dev/null || true
+    echo "[pve-mod] Created GPU RRD directory: $GPU_RRD_DIR"
+    exit 100
+fi
+
+exit 0