feat(audit, frontend, backend): introduce audit scripts and enhance error handling

- Added new npm scripts for auditing frontend size and inline TODOs, improving code quality management.
- Enhanced error handling in the `nuscoreApiRoutes` to return specific validation error statuses, improving API response clarity.
- Updated SQL migration documentation to establish a clear process for manual migrations and ensure backward compatibility.
- Refactored various components to align with new design standards, enhancing UI consistency across the application.

scripts/audit_frontend_size.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+TARGET_DIR="${1:-$ROOT_DIR/frontend/src}"
+WARN_BYTES=$((80 * 1024))
+REFACTOR_BYTES=$((120 * 1024))
+
+if [[ ! -d "$TARGET_DIR" ]]; then
+  echo "Directory not found: $TARGET_DIR" >&2
+  exit 1
+fi
+
+echo "Frontend size audit"
+echo "Target: $TARGET_DIR"
+echo "Warn threshold: ${WARN_BYTES} bytes (~80 KB)"
+echo "Refactor threshold: ${REFACTOR_BYTES} bytes (~120 KB)"
+echo
+
+find "$TARGET_DIR" -type f \( -name '*.vue' -o -name '*.js' -o -name '*.ts' -o -name '*.scss' \) -printf '%s %p\n' \
+  | sort -nr \
+  | awk -v warn="$WARN_BYTES" -v refactor="$REFACTOR_BYTES" '
+    BEGIN {
+      printf "%-12s %-12s %s\n", "Size (KB)", "Status", "File";
+      print "---------------------------------------------------------------";
+    }
+    {
+      size_bytes = $1;
+      size_kb = size_bytes / 1024;
+      $1 = "";
+      sub(/^ /, "", $0);
+      status = "ok";
+      if (size_bytes >= refactor) {
+        status = "refactor";
+      } else if (size_bytes >= warn) {
+        status = "warn";
+      }
+      printf "%-12.1f %-12s %s\n", size_kb, status, $0;
+    }
+  ' \
+  | sed -n '1,40p'

scripts/audit_inline_todos.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+
+echo "Inline TODO/FIXME audit"
+echo "Target: $ROOT_DIR/frontend/src + $ROOT_DIR/backend"
+echo
+
+if ! rg -n "TODO|FIXME|XXX" \
+  "$ROOT_DIR/frontend/src" \
+  "$ROOT_DIR/backend" \
+  -g '*.vue' \
+  -g '*.js' \
+  -g '*.ts' \
+  -g '*.scss' \
+  -g '*.sql' \
+  --glob '!**/dist/**' \
+  --glob '!**/node_modules/**' \
+  --glob '!**/package-lock.json'; then
+  echo "No inline TODO/FIXME/XXX markers found in product code."
+fi