feat(amazonq): introduce @workspace command to enhance chat quality (aws#6102)

## Problem
- workspace is no longer beta

## Solution
- remove beta indiciators

Author: Will-ShaoHua

packages/amazonq/.changes/next-release/Feature-64ebab3c-f06a-4df0-93bc-ca0891fd093f.json

@@ -0,0 +1,4 @@
+{
+	"type": "Feature",
+	"description": "Introduce @workspace command to enhance context fetching for Chat"
+}

packages/core/package.nls.json

@@ -74,7 +74,7 @@
     "AWS.configuration.description.amazonq": "Amazon Q creates a code reference when you insert a code suggestion from Amazon Q that is similar to training data. When unchecked, Amazon Q will not show code suggestions that have code references. If you authenticate through IAM Identity Center, this setting is controlled by your Amazon Q administrator. [Learn More](https://docs.aws.amazon.com/amazonq/latest/qdeveloper-ug/code-reference.html)",
     "AWS.configuration.description.amazonq.shareContentWithAWS": "When checked, your content processed by Amazon Q may be used for service improvement (except for content processed for users with the Amazon Q Developer Pro Tier). Unchecking this box will cause AWS to delete any of your content used for that purpose. The information used to provide the Amazon Q service to you will not be affected. See the [Service Terms](https://aws.amazon.com/service-terms) for more details.",
     "AWS.configuration.description.amazonq.importRecommendation": "Amazon Q will add import statements with inline code suggestions when necessary.",
-    "AWS.configuration.description.amazonq.workspaceIndex": "This feature is in BETA. When you add @workspace to your question in Amazon Q chat, Amazon Q will index your open workspace files locally to use as context for its response. Extra CPU usage is expected while indexing a workspace. This will not impact Amazon Q features or your IDE, but you may manage CPU usage by setting the number of local threads in 'Local Workspace Index Threads'.",
+    "AWS.configuration.description.amazonq.workspaceIndex": "When you add @workspace to your question in Amazon Q chat, Amazon Q will index your open workspace files locally to use as context for its response. Extra CPU usage is expected while indexing a workspace. This will not impact Amazon Q features or your IDE, but you may manage CPU usage by setting the number of local threads in 'Local Workspace Index Threads'.",
     "AWS.configuration.description.amazonq.workspaceIndexWorkerThreads": "Number of worker threads of Amazon Q local index process. '0' will use the system default worker threads for balance performance. You may increase this number to more quickly index your workspace, but only up to your hardware's number of CPU cores. Please restart VS Code or reload the VS Code window after changing worker threads.",
     "AWS.configuration.description.amazonq.workspaceIndexUseGPU": "Enable GPU to help index your local workspace files. Only applies to Linux and Windows.",
     "AWS.configuration.description.amazonq.workspaceIndexMaxSize": "The maximum size of local workspace files to be indexed in MB",

packages/core/src/amazonq/webview/ui/tabs/constants.ts

@@ -17,7 +17,7 @@ const workspaceCommand: QuickActionCommandGroup = {
     commands: [
         {
             command: '@workspace',
-            description: '(BETA) Reference all code in workspace.',
+            description: 'Reference all code in workspace.',
         },
     ],
 }