CVE-2026-45357: LiquidJS has a memory and render limit bypass via unbounded width padding in `date` filter (strftime)

The date filter’s strftime implementation parses width specifiers like %9999999d and forwards the captured width unchecked into pad()/padStart() in src/util/underscore.ts. The pad loop performs unbounded string concatenation without consulting the Context’s memoryLimit or renderLimit, so a single small template ({{ x | date: '%5000000d' }}) produces megabytes of output and unbounded CPU. The memoryLimit and renderLimit options the docs (src/liquid-options.ts:87-92) advertise as DoS controls — and which the docstring explicitly mentions for strftime — are entirely bypassed.