chore: update version to v0.3.0

- Bump version to 0.3.0
- Update CHANGELOG with 0.3.0 entries (billing link, timestamp, refresh button, remove dot)
- Update README tooltip description
- Update screenshots

Author: euxx

.github/assets/critical.png

@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## [0.3.0] - 2026-03-11
+
+- ⏱️ Show last-updated timestamp in tooltip (`Updated at HH:mm:ss`, or full date across days)
+- 📊 Add link icon in tooltip to open Premium request analytics on GitHub
+
 ## [0.2.0] - 2026-03-10
 
 - ⚙️ Reorganize threshold settings under `threshold.*` namespace (`threshold.enabled`, `threshold.warning`, `threshold.critical`)

.github/assets/normal.png

@@ -10,7 +10,7 @@
 ## Features
 
 - **Status bar**: shows used percentage (`15%`), turns yellow/red near threshold
-- **Hover tooltip**: plan, used / quota, overage (if any), reset date
+- **Hover tooltip**: plan, used / quota, overage (if any), reset date, last-updated timestamp — with a refresh button and a link to [Premium request analytics](https://github.com/settings/billing/premium_requests_usage)
 - **Auto-refresh**: configurable interval (default 5 min)
 - **Zero config**: uses your existing VS Code GitHub account sign-in
 

.github/assets/warning.png

@@ -2,7 +2,7 @@
   "name": "github-copilot-usage",
   "displayName": "GitHub Copilot Usage",
   "description": "Show GitHub Copilot Premium requests usage in the status bar.",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "author": "euxx",
   "license": "MIT",
   "repository": {