Blink: tokenize complex interpolation; ratchet mautic 0.07% and laravel 7.25%

[TomasVotruba]

Teaches blink's lexer to tokenize complex {$...} interpolation, clearing the last reflow-able mautic diff, and ratchets both parity gates.

Lexer: complex interpolation

blink folded every double-quoted string into one atomic token, so it could not reflow an array embedded in an interpolated string. lexInterpolatedString now splits a double-quoted string that contains a complex {$...} interpolation into: a literal chunk ending at {, the inner expression lexed as real tokens, a chunk starting at }, repeated, then the closing chunk. The quote, braces, and all literal text stay in the emitted string chunks, so Render stays byte-exact. Simple $var, ${...}, single-quoted strings and heredocs are untouched. Nested, multiple, and escaped interpolations are handled via brace-depth tracking. One consumer (ExplicitStringVariable) was updated to treat a }-leading continuation chunk as interpolation body.

Array fixers can now see the [...] inside "...{$this->translator->trans('...', [ ... ])}..." and reflow it - fixing SummarizeCommand.

Round-trip proven byte-identical across 4737 mautic files, 17 rector-src files, and 9 hand-written edge cases (nested dynamic access, multiple interps, embedded arrays, escapes, embedded quotes, ${simple}).

Gates

• mautic: 0.1% -> 0.07% (actual 0.066%, 3 of 4527). The remaining 3 are upstream php-cs-fixer/Symplify bugs that can only be matched by bug-for-bug emulation that is not provably rector-gate-safe (two .html.php inline-HTML ArrayIndentation artifacts; FieldsTypeTrait's TokenSkipper::skipBlocksReversed not skipping closure/destructuring blocks).
• laravel: 7.3% -> 7.25% (actual 7.199%, 219 of 3042). Small step - laravel parity needs a dedicated campaign to move meaningfully, and laravel/framework drifts daily, so the margin is kept modest to avoid flakiness.

Full blink suite, go vet, golangci-lint green; strict rector-src 1:1 gate stays 0-diff; zero mautic regressions.