Add `and` and `or` logical operators to WHERE clause operations

[anatolzak]

Summary

The WHERE clause callback currently provides comparison operations (eq, ne, gt, exists, etc.) but no logical operators. Users who need AND/OR must manually compose template literal strings:

.where(({ from, to }, { lte, gte, notExists }) => {
  return `${lte(from, epoch)} AND (${gte(to, epoch)} OR ${notExists(to)})`;
})

This proposal adds and and or as first-class operations:

.where(({ from, to }, { lte, gte, notExists, and, or }) => {
  return and(lte(from, epoch), or(gte(to, epoch), notExists(to)));
})

Motivation

• Consistency — comparison operators are functions, but logical composition requires string interpolation
• Composability — and/or can be nested arbitrarily: or(and(...), and(...))
• Conditional expressions — accepts undefined values (filtered out), enabling Drizzle ORM-style patterns:

.where(({ animal, dangerous }, { eq, exists, or }) =>
  or(
    eq(animal, "Cow"),
    shouldFilterDangerous ? exists(dangerous) : undefined,
  )
)

Behavior

• and(...expressions) / or(...expressions) — joins with AND / OR, wrapped in parentheses
• Single argument — returns unwrapped
• No arguments or all undefined — returns empty string
• Accepts (string | undefined)[]
• Fully backward compatible — existing template literal usage continues to work