Add company overview skeleton and cache

drizzle/0012_company_overview_cache.sql

@@ -0,0 +1,15 @@
+CREATE TABLE `company_overview_cache` (
+	`id` integer PRIMARY KEY AUTOINCREMENT NOT NULL,
+	`user_id` text NOT NULL,
+	`ticker` text NOT NULL,
+	`cache_version` integer NOT NULL,
+	`source_signature` text NOT NULL,
+	`payload` text NOT NULL,
+	`created_at` text NOT NULL,
+	`updated_at` text NOT NULL,
+	FOREIGN KEY (`user_id`) REFERENCES `user`(`id`) ON UPDATE no action ON DELETE cascade
+);
+--> statement-breakpoint
+CREATE UNIQUE INDEX `company_overview_cache_uidx` ON `company_overview_cache` (`user_id`,`ticker`);
+--> statement-breakpoint
+CREATE INDEX `company_overview_cache_lookup_idx` ON `company_overview_cache` (`user_id`,`ticker`,`updated_at`);