[Bug] BigModel provider unavailable after successful login: providerCount=0, no models selectable, Weekend Build card missing

提交前确认 · Pre-submission checklist

• 我已搜索过现有 issue，确认这不是重复 / I searched existing issues and confirmed this isn't a duplicate.
• 我已阅读 CONTRIBUTING.md / I've read CONTRIBUTING.md.

问题类别 · Category

模型设置 / 切换 · Model config

涉及的 Agent 框架 · Agent framework

ZCode Agent（自研）

严重程度 · Severity

阻塞使用 · Blocking (无法使用核心功能 / core function unusable)

复现频率 · Reproducibility

必现 · Always

问题描述 · Description

After successfully signing in to BigModel on ZCode 3.12.3 (Windows x64), the built-in BigModel provider remains unavailable and no model can be selected.

Symptoms:

• The model selector contains no selectable models and only shows "Manage Models".
• Model Settings displays GLM-5.3 and GLM-5.3-Flash, but testing GLM-5.3-Flash fails with:
  BigModel Individual Coding Plan / GLM-5.3-Flash connection failed: provider currently unavailable.
• The current Weekend Build 300M GLM-5.3-Flash claim card is missing.
• Usage Stats cannot be loaded and shows a network/provider configuration error.

Relevant diagnostic information:

• BigModel OAuth login completes successfully.
• Provider Registry becomes ready with providerCount: 0.
• ZCode Agent reports that no model provider/model is available.
• The billing/balance request succeeds, but returns plans: [] and balances: [].
• ZCode reports that no usable BigModel entitlement was found.
• coding-plan-subscription.getManualClaimPlanPreviews and client-scenes.list both return OK.
• usage-stats.getAppUsageSnapshot fails with no_active_workspace.

I have already tried:

• Logging out and signing in again.
• Fully quitting ZCode from the Windows system tray and restarting it.
• Confirming that ZCode is already on version 3.12.3.
• Testing with the proxy disabled.
• My TUN configuration had previously worked normally.

A custom data directory is enabled.

I also submitted a full diagnostic report through the in-app feedback system:

Feedback ID: ZCT-2101169417505722368

Possibly related to #549, but this case is more severe because all built-in BigModel models are unavailable, not only the Weekend Build claim card.

复现步骤 · Steps to reproduce

1. Start ZCode 3.12.3 on Windows x64.
2. Sign in to a BigModel account successfully.
3. Open a local workspace/project.
4. Open the model selector in the chat composer.
5. Observe that no model is available and only "Manage Models" is shown.
6. Go to Settings -> Model Settings -> BigModel.
7. Observe that GLM-5.3 and GLM-5.3-Flash are listed.
8. Test GLM-5.3-Flash.
9. Observe that ZCode reports the provider is currently unavailable.
10. Go to Settings -> Usage Stats.
11. Observe that usage data cannot be loaded.
12. Return to the main workspace and observe that the Weekend Build 300M claim card is also missing.

期望表现 · Expected behavior

After a successful BigModel login, the eligible BigModel provider should be registered and available.

GLM-5.3 / GLM-5.3-Flash should appear in the model selector and be usable.

If the account is eligible for the active Weekend Build promotion, the claim card should appear and allow the user to claim the promotional GLM-5.3-Flash quota.

Usage Stats should also load normally.

实际表现 · Actual behavior

BigModel login succeeds, but Provider Registry remains at providerCount=0.

No built-in model can be selected.

GLM-5.3-Flash reports that the provider is unavailable, the Weekend Build claim card is missing, and Usage Stats fails to load.

The server-side billing request itself succeeds but returns no plans or balances, and ZCode reports that no usable BigModel entitlement was found.

ZCode 版本 · ZCode version

3.12.3

设备 / 系统 / 浏览器 · Device / OS / Browser

Windows x64 / ZCode Desktop App / custom data directory enabled

截图 / 录屏 / 日志 · Screenshots / Recordings / Logs

Relevant sanitized log excerpts:

[provider-runtime]
Provider Registry ready ... "providerCount":0

[zcode-agent-service]
No available model provider/model is currently available.

[coding-plan-availability]
billing/balance request completed:
"success":true
"plans":[]
"balances":[]

[usage-stats]
BigModel entitlement: no usable authorization found

[rpc:call]
coding-plan-subscription.getManualClaimPlanPreviews OK

[rpc:call]
client-scenes.list OK

[rpc:call]
usage-stats.getAppUsageSnapshot FAIL
message: "no_active_workspace"

Full diagnostic logs have already been submitted through the ZCode in-app feedback system.

Feedback ID: ZCT-2101169417505722368

Start by tracing the Provider Registry and model selector after BigModel OAuth login, then inspect the billing/balance, coding-plan-subscription, client-scenes.list, and usage-stats.getAppUsageSnapshot entry points described in the report. Compare the providerCount, plans, balances, and entitlement results to the expected registration flow. Done means eligible BigModel models are selectable, the Weekend Build card appears when applicable, and Usage Stats loads.