stripHtmlTags silently swallows allocation errors

[calin-marian]

Problem

stripHtmlTags in formatter.zig uses catch {} on result.append(allocator, ...) calls, silently discarding allocation failures. Since the function returns ![]u8 (can propagate errors), these should use try instead. Silent failures can produce truncated or corrupted output without any indication.

Fix

Changed all catch {} on append calls in stripHtmlTags to try, so allocation errors propagate to the caller.

References

Fixed in PR #7 (commit 1e12dd1). Also affects PRs #8 and #9 via rebase.