Bug fixes : SSE import completion, SQL comment parsing, and UI improvements

[w3spi5]

Summary

• SSE Import Completion: Display success message in-page instead of redirecting to error page after import finishes
• SQL Comment Parsing: Fix -- comment handling in SqlParser that was breaking certain dump files
• Preview Button Alignment: Fix vertical alignment of preview icon button in file list

Changes

SSE Import Success Display

Previously, when an SSE import completed successfully, location.reload() redirected to /import which showed "No filename specified" error because the session was already cleared.

Now displays a styled success message in-page with:

• Import statistics (queries, lines, bytes, duration)
• "Back to Home" button

SQL Parser Fix

Fixed edge case where -- inside string literals was incorrectly treated as a comment delimiter.

UI Fix

Corrected vertical alignment of the preview button to match other action buttons in the file list.