1.18.1

A small fix-up for 1.18.0: series shelves report target progress honestly, generated covers put the title where it belongs, and the store's CSS warnings are cleared.

Fixed

• A series shelf's target percentage no longer runs away when only some books have a target. The header added up every book's words but only the targeted books' targets, so one book with a 60,000-word target in a 353,000-word series read "588%". Progress now counts only the targeted books' words and says so — 3 books · 353,412 words · 21,040 / 60,000 targeted (35%). A shelf where every book has a target reads as before. Reported in #44.
• Generated book covers sit their title at the bottom, as designed. A book card without cover art shows its title on a tinted stand-in; a conflicting style kept the title pinned to the top. It now sits at the bottom of the cover, still clamped to five lines.
• Store CSS lint warnings cleared. The "Add to series…" line's dotted underline and the generated-cover style no longer trip the community-store CSS checks; the look is unchanged.