feat: add saved views — database table, CRUD API, migration

- New views table (id, name, filters jsonb, sort_key, is_public, creator_id)
- GET/POST/PATCH/DELETE /views endpoints
- Register views router in server

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

drizzle/migrations/0003_dry_caretaker.sql

@@ -0,0 +1,12 @@
+CREATE TABLE "views" (
+	"id" uuid PRIMARY KEY DEFAULT gen_random_uuid() NOT NULL,
+	"name" text NOT NULL,
+	"filters" jsonb DEFAULT '[]' NOT NULL,
+	"sort_key" text DEFAULT 'updated',
+	"columns" jsonb DEFAULT '[]',
+	"is_public" boolean DEFAULT false,
+	"creator_id" uuid,
+	"created_at" timestamp with time zone DEFAULT now()
+);
+--> statement-breakpoint
+ALTER TABLE "views" ADD CONSTRAINT "views_creator_id_users_id_fk" FOREIGN KEY ("creator_id") REFERENCES "public"."users"("id") ON DELETE no action ON UPDATE no action;