Slice 3 setup: Tailwind v4 + DaisyUI v5 (dracula enabled) + 'tab' vocab

- add tailwindcss@4 + @tailwindcss/vite + daisyui@5; vite tailwind plugin
- src/app.css: @import tailwindcss + @plugin daisyui { themes: dracula --default }
  (theme BUNDLED, not just named); imported in main.ts
- index.html: <html data-theme="dracula">
- biome.json: enable css tailwindDirectives so @plugin parses
- GLOSSARY: define FE term 'tab' (workspace slot referencing a conversation;
  holds conversationId + model + title; close = local forget)

Verified: dracula tokens bundled in CSS, svelte-check 0/0, vitest 222, biome
clean, build ok.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/app.css b/src/app.css
new file mode 100644
index 0000000..37131d3
--- /dev/null
+++ b/src/app.css
@@ -0,0 +1,8 @@
+@import "tailwindcss";
+
+/* DaisyUI v5 — enable the plugin AND bundle the dracula theme (set as default,
+   applied via <html data-theme="dracula">). Themes not listed here are NOT
+   bundled, so dracula must be named explicitly, not merely referenced. */
+@plugin "daisyui" {
+	themes: dracula --default;
+}