Added Github API rate limiting

- Implemented comprehensive GitHub API rate limit handling:
    - Integrated @octokit/plugin-throttling for automatic retry with exponential backoff
    - Added RateLimitManager service to track and enforce rate limits
    - Store rate limit status in database for persistence across restarts
    - Automatic pause and resume when limits are exceeded
    - Proper user identification for 5000 req/hr authenticated limit (vs 60 unauthenticated)

  - Improved rate limit UI/UX:
    - Removed intrusive rate limit card from dashboard
    - Toast notifications only at critical thresholds (80% and 100% usage)
    - All rate limit events logged for debugging

  - Optimized for GitHub's API constraints:
    - Reduced default batch size from 10 to 5 repositories
    - Added documentation about GitHub's 100 concurrent request limit
    - Better handling of repositories with many issues/PRs

drizzle/0004_grey_butterfly.sql

@@ -0,0 +1,18 @@
+CREATE TABLE `rate_limits` (
+	`id` text PRIMARY KEY NOT NULL,
+	`user_id` text NOT NULL,
+	`provider` text DEFAULT 'github' NOT NULL,
+	`limit` integer NOT NULL,
+	`remaining` integer NOT NULL,
+	`used` integer NOT NULL,
+	`reset` integer NOT NULL,
+	`retry_after` integer,
+	`status` text DEFAULT 'ok' NOT NULL,
+	`last_checked` integer NOT NULL,
+	`created_at` integer DEFAULT (unixepoch()) NOT NULL,
+	`updated_at` integer DEFAULT (unixepoch()) NOT NULL,
+	FOREIGN KEY (`user_id`) REFERENCES `users`(`id`) ON UPDATE no action ON DELETE no action
+);
+--> statement-breakpoint
+CREATE INDEX `idx_rate_limits_user_provider` ON `rate_limits` (`user_id`,`provider`);--> statement-breakpoint
+CREATE INDEX `idx_rate_limits_status` ON `rate_limits` (`status`);

drizzle/meta/_journal.json

@@ -29,6 +29,13 @@
       "when": 1757390828679,
       "tag": "0003_open_spacker_dave",
       "breakpoints": true
+    },
+    {
+      "idx": 4,
+      "version": "6",
+      "when": 1757392620734,
+      "tag": "0004_grey_butterfly",
+      "breakpoints": true
     }
   ]
 }