fix(filter): allow bare @ adjacent to an operator without whitespace

[spokodev]

Bug

A filter with a bare @ (the current node) placed directly against an operator, with no whitespace, fails to evaluate:

JSONPath({json: [0, 1, 2, 3], path: '$[?(@>1)]'});
// Error: Unexpected "@" at character 0   (safe eval)
// Error: Invalid or unexpected token     (native eval)

The same query works only if a space is added: $[?(@ > 1)].

Cause

In _eval, the current-node token @ is rewritten to the sandbox variable _$_v by:

.replaceAll(/@([.\s)[])/gu, '_$_v$1');

The character class only allows @ to be followed by ., whitespace, ) or [. When @ is immediately followed by a comparison or arithmetic operator (>, <, ==, !=, %, +, -, *, /, &, |), it is left as a literal @, so the compiled filter script begins with @ and neither the safe (jsep) nor the native (vm) evaluator can parse it.

Fix

Add those operator characters to the delimiter class:

.replaceAll(/@([-.\s)[<>=!%*/+&|])/gu, '_$_v$1');

@ inside identifiers and quoted keys is still protected (it is only rewritten when followed by an operator/delimiter, never a word character), so cases like @['@tag'] are unaffected.

Adds a regression test covering @>, @<, @=== and @!== with no surrounding whitespace. Full suite passes and lint is clean.