feat(amazonq): paid tier

[justinmk3]

Problem

When Builder Id customers hit the "free tier" limit, there is no guidance.

Solution

• Update to latest Flare release, which:

  • auto-detects when the free-tier limit is reached
  • shows a chat card with an inputbox for aws account id
  • handles when the user clicks "Upgrade"
  • waits for upgrade to complete and updates chat UI

• Add a Manage Subscriptions menu item, which invokes the Flare aws/chat/manageSubscription command.

• Handle ShowDocumentParams.external. This is a standard lsp interface, and is required by the new Flare logic.

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• Treat all work as PUBLIC. Private feature/x branches will not be squash-merged at release time.
• Your code changes must meet the guidelines in CONTRIBUTING.md.
• License: I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions]

• This pull request implements a feat or fix, so it must include a changelog entry (unless the fix is for an unreleased feature). Review the changelog guidelines.
  • Note: beta or "experiment" features that have active users should announce fixes in the changelog.
  • If this is not a feature or fix, use an appropriate type from the title guidelines. For example, telemetry-only changes should use the telemetry type.