refactor: convert to bun workspaces monorepo

- Move web app into apps/web/
- Create packages/shared/ with shared types
- Create plugins/decky-vault/ scaffold
- Root package.json manages workspaces only

apps/web/drizzle/0021_demonic_texas_twister.sql

@@ -0,0 +1,11 @@
+CREATE TABLE "saved_filters" (
+	"id" text PRIMARY KEY NOT NULL,
+	"user_id" text NOT NULL,
+	"name" text NOT NULL,
+	"filters" jsonb NOT NULL,
+	"created_at" timestamp DEFAULT now() NOT NULL,
+	"updated_at" timestamp DEFAULT now() NOT NULL,
+	CONSTRAINT "saved_filters_user_name" UNIQUE("user_id","name")
+);
+--> statement-breakpoint
+ALTER TABLE "saved_filters" ADD CONSTRAINT "saved_filters_user_id_user_id_fk" FOREIGN KEY ("user_id") REFERENCES "public"."user"("id") ON DELETE cascade ON UPDATE no action;