feat(diagnostics): bridge generate failures to diagnose() hypotheses (#130)

[hqhq1025]

Summary

Test-connection 失败已经走 `diagnose()` 给出可操作 hypothesis（如 404 → `missingV1` + 自动加 `/v1`），但真实生成失败完全没接这套系统，用户只看到原始 IPC 错误文案，毫无方向。

本 PR 把 generate 失败接到 diagnostic hypothesis 系统，覆盖 404/4xx/5xx 多种场景，并为 404 missing-`/v1` 加自动 fix 按钮。

What changed

main 进程

• `apps/desktop/src/main/index.ts`：generate catch 块给 thrown error 附加 `upstream_status` / `upstream_provider` / `upstream_baseurl` / `upstream_wire` metadata
• 新增 helper `extractUpstreamHttpStatus()`

shared

• 新增 `diagnoseGenerateFailure()` in `packages/shared/src/diagnostics.ts`：
  • 400 + "instructions" 关键词 → `openaiResponsesMisconfigured` + `switchWire` 提示
  • 5xx + "not implemented" / "page not found" → `gatewayIncompatible` + `switchWire` 提示
  • 通用 5xx → `serverError` + `waitAndRetry`
  • 404（含裸 "404 page not found" 文案，bug(desktop): generation fails with codesign:v1:generate 404 on Win11 relay setup #130 原始形态）→ `missingV1` + `/v1` 自动 fix
  • 401/403/429/402 → 委托现有 `diagnose()`
  • 其它 → `unknown`（toast 跳过避免噪音）

renderer

• `apps/desktop/src/renderer/src/store.ts` `applyGenerateError`：调用 `diagnoseGenerateFailure` 把 cause sentence 拼到 toast description；404 missing-`/v1` case 加 "Apply fix" action button 通过 `config:v1:update-provider` 自动加 `/v1`

i18n（en + zh-CN）

• `diagnostics.cause.{gatewayIncompatible,openaiResponsesMisconfigured,serverError}`
• `diagnostics.fix.switchWire`
• `notifications.{generationFailedApplyFix,generationFailedBaseUrlUpdated}`

Design trade-offs

• 新增 `diagnoseGenerateFailure` 而非扩展 `diagnose()` —— connection-test 传 `ErrorCode`，generate 传 `{status, message, wire, ...}`，重载会很别扭
• status 提取：先读 `err.upstream_status`，fallback 到 message regex —— Electron IPC 在某些版本会剥掉 custom Error props
• 404 auto-fix 按钮只对 missing-`/v1` 实现，其它 hypothesis 只有提示文本（updateKey/switchWire/addCredits 需要用户判断）

Test plan

• 10 new tests in `diagnostics.test.ts`（25/25 pass）
• 870/870 desktop tests green
• `pnpm typecheck` + `pnpm lint` clean

Follow-up

• 403 "Your request was blocked" / Cloudflare ray id 的 `gatewayWafBlocked` 分支（issue 正常对话时报 403 错误：Error invoking remote method 'codesign:v1:generate' #124 专用）将在后续 commit 追加
• 其它 hypothesis 的 auto-fix 按钮（如 switchWire one-click）

Closes #130
Refs #124, #134, #158

[github-actions]

Findings

• [Blocker] Silent fallback when fix-apply IPC is unavailable — violates the project rule that errors must surface instead of failing silently; if window.codesign?.config?.updateProvider is missing, clicking “Apply fix” does nothing with no user-visible error, evidence apps/desktop/src/renderer/src/store.ts:1149
  Suggested fix:

  const api = window.codesign?.config?.updateProvider;
  if (api === undefined) {
    get().reportableErrorToast({
      code: 'GENERATE_FIX_APPLY_FAILED',
      scope: 'generate',
      title: tr('notifications.generationFailed'),
      description: tr('errors.rendererDisconnected'),
    });
    return;
  }

Summary

• Review mode: initial
• 1 blocker found in modified lines.
• docs/VISION.md and docs/PRINCIPLES.md: Not found in repo/docs.

Testing

• Not run (automation)
• Suggested tests: add a Vitest case for applyGenerateBaseUrlFix path where window.codesign?.config?.updateProvider is unavailable, asserting an error toast is emitted.

open-codesign Bot

[github-actions]

[Blocker] This introduces a silent fallback (if (api === undefined) return;). Project constraints require surfacing every error. If preload/API wiring is missing, clicking Apply fix currently no-ops with no feedback.

Suggested minimal change:

const api = window.codesign?.config?.updateProvider;
if (api === undefined) {
  get().reportableErrorToast({
    code: 'GENERATE_FIX_APPLY_FAILED',
    scope: 'generate',
    title: tr('notifications.generationFailed'),
    description: tr('errors.rendererDisconnected'),
  });
  return;
}

[github-actions]

Findings

• No actionable issues found in added/modified lines with >=80% confidence.

Summary

• Review mode: follow-up after new commits
• No new issues found in the latest diff.
• docs/VISION.md and docs/PRINCIPLES.md: Not found in repo/docs.
• Residual risk: diagnoseGenerateFailure relies on message-text heuristics; future provider message variations may reduce classification accuracy.

Testing

• Not run (automation)
• Suggested tests: add a renderer-level Vitest for applyGenerateError that asserts (1) 404 message path appends the most-likely-cause sentence and (2) missing-/v1 hypothesis exposes an Apply-fix action.

open-codesign Bot