Gracefully catch unexpected html (non json) response from external services

[alfonso-noriega]

WHY are these changes introduced?

Issue #1325

Vault error

Observe error

JSON parsing errors in HTTP responses were causing unhandled exceptions and poor error messages when external services return malformed responses or are temporarily unavailable.

WHAT is this pull request doing?

Add proper error handling for JSON parsing failures in HTTP response processing across three modules:

• Token exchange service: Wrap JSON parsing in try-catch and throw descriptive BugError when identity service returns invalid JSON
• GitHub API client: Handle JSON parsing errors when fetching release information and provide clear error messaging
• Admin authentication: Add error handling for malformed responses from the admin authentication service

All error messages inform users that the service may be temporarily unavailable and suggest retrying.

Measuring impact

How do we know this change was effective? Please choose one:

• n/a - this doesn't need measurement, e.g. a linting rule or a bug-fix
• Existing analytics will cater for this addition
• PR includes analytics changes to measure impact

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes

[alfonso-noriega]

• Gracefully catch unexpected html (non json) response from external services #6873 👈 (View in Graphite)
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	78.89%	14560/18457
🟡	Branches	73.22%	7222/9863
🟡	Functions	79.09%	3704/4683
🟡	Lines	79.23%	13767/17375

Test suite run success

3777 tests passing in 1455 suites.

Report generated by 🧪jest coverage report action from 9d4ac4e

[github-actions]

We detected some changes at packages/*/src and there are no updates in the .changeset.
If the changes are user-facing, run pnpm changeset add to track your changes and include them in the next release CHANGELOG.

Caution

DO NOT create changesets for features which you do not wish to be included in the public changelog of the next CLI release.