Replace \s+ with [^\S\n]+ to preserve newlines

[mattn]

extractText in pkg/tools/web.go replaces all whitespace (including newlines) with a single space using \s+, then tries to split by \n to filter empty lines. Since all newlines are already gone, the output is always a single line.

[Leeaandrob]

@Zepan This PR by @mattn replaces \s+ with [^\S\n]+ in regex patterns to preserve newlines. This is a subtle but important fix — without it, multi-line content gets collapsed into single lines.

Recommendation: Merge. Correct regex behavior that preserves formatting. Well-tested by a contributor who clearly understands Go regex edge cases.