chore(quality): fix release-tip base-reds — providerTierField case collision + stryker 7806 registration

(1) #7838 added providerTierField.ts next to ProviderTierField.tsx in the same
directory — a case-only collision that breaks webpack on case-insensitive
filesystems; the #6584 guard fails Unit shard 4/4 on every fresh PR run.
Rename the helper to providerTierFieldApi.ts (import + test path adjusted).
(2) check:mutation-test-coverage --strict fails on the tip because merged
#7806's combo-skip-conn-disable-plugin-block test was never registered in
stryker tap.testFiles. Register it.

changelog.d/maintenance/7838-7806-basereds-case-collision-stryker.md

@@ -0,0 +1 @@
+- **chore(quality):** fix two release-tip base-reds blocking every fresh PR run: rename `providerTierField.ts` → `providerTierFieldApi.ts` (case-only filename collision with `ProviderTierField.tsx` from #7838 — breaks webpack on case-insensitive filesystems, caught by the #6584 guard) and register `combo-skip-conn-disable-plugin-block-7806.test.ts` (from merged #7806) in stryker `tap.testFiles`.

src/app/(dashboard)/dashboard/providers/[id]/components/modals/ProviderTierField.tsx

@@ -4,7 +4,7 @@ import { useEffect, useState } from "react";
 import { useTranslations } from "next-intl";
 import { Select } from "@/shared/components";
 import type { ProviderTier } from "@omniroute/open-sse/services/tierTypes";
-import { fetchProviderTierOverride, saveProviderTierOverride } from "./providerTierField";
+import { fetchProviderTierOverride, saveProviderTierOverride } from "./providerTierFieldApi";
 
 export interface ProviderTierFieldProps {
   /** Provider connection id string — the same key `classifyTier()` matches on. */

stryker.conf.json

@@ -154,6 +154,7 @@
       "tests/unit/combo-scoring-inspector.test.ts",
       "tests/unit/combo-selected-connection-success.test.ts",
       "tests/unit/combo-sessionless-pin-3825.test.ts",
+      "tests/unit/combo-skip-conn-disable-plugin-block-7806.test.ts",
       "tests/unit/combo-speed-telemetry-6875.test.ts",
       "tests/unit/combo-strategies.test.ts",
       "tests/unit/combo-strategy-fallbacks.test.ts",

tests/unit/provider-tier-field-helpers.test.ts

@@ -7,7 +7,7 @@ import test from "node:test";
 import assert from "node:assert/strict";
 
 const { normalizeTierValue, fetchProviderTierOverride, saveProviderTierOverride } = await import(
-  "../../src/app/(dashboard)/dashboard/providers/[id]/components/modals/providerTierField.ts"
+  "../../src/app/(dashboard)/dashboard/providers/[id]/components/modals/providerTierFieldApi.ts"
 );
 
 type FetchCall = { url: string; init?: RequestInit };