Slice 1: surface system + WS transport + composition root

Pure-core feature libraries assembled at the composition root:
- core/protocol: pure reducer over surface catalog/spec/error messages
- features/surface-host: generic field-kind interpreter (toggle/progress/
  selector/stat/button) + pure plan logic; no surface-id special-casing
- adapters/ws: injected WebSocket client (effects at the edge)
- app: composition root store (Svelte 5 runes over the pure reducer),
  host-relative surface WS URL resolution (resolveWsUrl), root App.svelte

Verified green: svelte-check 0/0, vitest 84 passed, biome clean, vite build ok.

1 files changed, 10 insertions, 0 deletions

diff --git a/biome.json b/biome.json
new file mode 100644
index 0000000..7179b96
--- /dev/null
+++ b/biome.json
@@ -0,0 +1,10 @@
+{
+	"$schema": "https://biomejs.dev/schemas/2.4.16/schema.json",
+	"assist": { "actions": { "source": { "organizeImports": "on" } } },
+	"linter": { "enabled": true, "rules": { "recommended": true } },
+	"formatter": { "enabled": true, "indentStyle": "tab", "lineWidth": 100 },
+	"javascript": { "formatter": { "quoteStyle": "double", "semicolons": "always" } },
+	"files": {
+		"includes": ["**", "!**/node_modules", "!**/dist", "!**/build", "!**/*.svelte"]
+	}
+}