Overhaul bottom bar: batch add, custom fields, stat block viewer

Unify the action bar into a single search input with inline bestiary
dropdown. Clicking a dropdown entry queues it with +/- count controls
and a confirm button; Enter or confirm adds N copies to combat.

When no bestiary match exists, optional Init/AC/MaxHP fields appear
for custom creatures. The eye icon opens a separate search dropdown
to preview stat blocks without leaving the add flow.

Fix batch-add bug where only the last creature got a creatureId by
using store.save() instead of setEncounter() in addFromBestiary.
Prevent dropdown buttons from stealing input focus so Enter confirms
the queued batch.

Remove the now-redundant BestiarySearch component.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -4,7 +4,7 @@ A local-first initiative tracker and encounter manager for tabletop RPGs (D&D 5e
 
 ## What it does
 
-- **Initiative tracking** — add combatants, roll initiative (manual or d20), cycle turns and rounds
+- **Initiative tracking** — add combatants (batch-add from bestiary, custom creatures with optional stats), roll initiative (manual or d20), cycle turns and rounds
 - **Encounter state** — HP, AC, conditions, concentration tracking with visual status indicators
 - **Bestiary integration** — import bestiary JSON sources, search creatures, and view full stat blocks
 - **Persistent** — encounters survive page reloads via localStorage; bestiary data cached in IndexedDB