fix(eslint-plugin): enforce-update-with-where false positive when .from() precedes .where()

[Yanhu007]

Summary

Fixes #5612

The enforce-update-with-where rule incorrectly flags update chains where .from() appears before .where():

// ❌ Incorrectly flagged as missing .where()
await tx
  .update(table)
  .set({ ... })
  .from(sql\`(VALUES ...) AS v(...)\`)
  .where(eq(table.id, v.id));

Root Cause

The rule used a module-level lastNodeName variable to track whether .where() appeared before .set() in AST traversal order. Since ESLint visits nodes depth-first, the .set() MemberExpression is visited before the outer .from().where() chain — so lastNodeName is never 'where' when the rule checks.

This approach also has a secondary issue: the global variable leaks state across unrelated expressions in the same file.

Fix

Replace the lastNodeName approach with a chainContainsWhere() function that walks upward through the AST from the .set() node, following the CallExpression → MemberExpression chain pattern, to check if .where() exists anywhere in the method chain.

Tests

Added valid cases for .from().where() chains.