Critical Billing Error: Charged $13.51 for Pro Subscription while Account is Stuck on Free Tier

### Checks

- [x] I have searched [github.com/aws/amazon-q-developer-cli/issues](https://github.com/aws/amazon-q-developer-cli/issues?q=) and there are no duplicates of my issue
- [x] I have run `q doctor` in the affected terminal session
- [x] I have run `q restart` and replicated the issue again

### Operating system

macOS 13.5.1 (22G90)

### Expected behaviour

- The billing state should perfectly sync with the provisioned tier. If the user remains on the Free tier, no Pro charges should be issued.
- A functional "Manage Subscription" or "Cancel Subscription" portal should always be visible to users to prevent unauthorized recurring automated retries.
- A manual billing reconciliation and full refund of the $13.51 USD discrepancy.

### Actual behaviour

- Account Sign-in Method: AWS Builder ID
- Impacted Account: (Will provide the specific Gmail / Builder ID privately to the maintainers/support team upon request to protect personal privacy)
- Transaction Date: June 1st, 2026
- Charge Amount: $13.51 USD

### Steps to reproduce

### Scenario A: Charged but stuck on Free tier (Account: `zhaojunv85+02@gmail.com`)
1. Initiate a subscription/signup flow using **AWS Builder ID** with the email `zhaojunv85+02[at]gmail.com`.
2. Opt into the **Kiro Pro Free Trial** ($0 onboarding/verification promotion) by linking a valid Mastercard.
3. The card verification process succeeds on the billing gateway side (Stripe/AWS Marketplace).
4. **The Bug:** After redirection back to the platform, the backend provisioning fails to sync. The user dashboard still reflects **"Kiro Free"** (0/50 credits covered), and Pro agent capabilities remain locked.
5. **The Consequence:** Upon the next billing cycle/reset, the system triggers an automatic renewal charge, wrongfully debiting **$13.51 USD** from the card without ever activating the Pro tier features.

### Scenario B: Ghost subscription retry loop with no cancellation option (Account: `zhaojunv85+03@gmail.com`)
1. Register/Sign in to a separate account `zhaojunv85+03[at]gmail.com` via AWS Builder ID.
2. Attempt the same subscription onboarding flow, which similarly encounters a provisioning failure, trapping the account on the **Free tier**.
3. Because the frontend UI incorrectly considers the user to be on the "Free Plan", the **"Manage Subscription" or "Cancel" portal completely disappears** from the settings dashboard. There is no UI element available to remove the payment method or revoke authorization.
4. **The Consequence:** The billing backend constantly fires recurring, unauthorized payment retries (e.g., $8.29 USD via Stripe) against the card. Since the user cannot access any cancellation buttons, they are trapped in an endless background billing retry loop.

### Environment

```yaml

[q-details]
version = "2.5.1"
hash = "f8525c88fe5af180a0384de573ed1a9d358f2f17"
date = "2026-05-30T00:09:16.40791Z (5d ago)"
variant = "full"

[system-info]
os = "macOS 13.5.1 (22G90)"
chip = "Intel(R) Core(TM) i5-7360U CPU @ 2.30GHz"
total-cores = 2
memory = "16.00 GB"

[environment]
os = "Mac"
shell-path = "/bin/zsh"
shell-version = "5.9"
install-method = "unknown"

[env-vars]
PATH = "/usr/local/opt/mysql@5.7/bin:/usr/local/opt/openssl@1.1/bin:/usr/local/opt/llvm@15/bin:/usr/local/opt/gnu-sed/libexec/gnubin:/usr/local/anaconda3/bin:/Users/USER/apache-maven/bin:/Users/USER/.tiup/bin:/Users/USER/.codeium/windsurf/bin:/Users/USER/.antigravity/antigravity/bin:/Users/USER/.bun/bin:/Users/USER/.opencode/bin:/Users/USER/.local/bin:/Users/USER/bin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Applications/VMware Fusion.app/Contents/Public:/usr/local/go/bin:/usr/local/MacGPG2/bin:/Library/Apple/usr/bin:/Applications/Wireshark.app/Contents/MacOS:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/Users/USER/.cargo/bin:/Applications/Warp.app/Contents/Resources/bin"
Q_SET_PARENT_CHECK = "1"
SHELL = "/bin/zsh"
TERM = "xterm-256color"
__CFBundleIdentifier = "dev.warp.Warp-Stable"
```