fix(cli): remove orphaned resolveOpencodeConfigDir re-export (base-red #9985)

`check:dead-code` reports 410 dead symbols against a 409 baseline on the
pristine `release/v3.8.50` tip, so every PR on the branch is born red on that
gate (#10386, #10393, #10390, #10388, #10382 all fail it).

Isolated the +1 by diffing knip 6.32 reports between the rebaseline commit
97aac6ac6c (409) and the tip (410): `resolveOpencodeConfigDir` in
`src/shared/services/cliRuntime.ts`. #10246 moved the canonical resolvers into
`opencodeConfigPath.ts` and left this wrapper behind; the same commit removed
its last consumer.

The wrapper was not just unused, it was divergent: it returned
`path.dirname()` of the canonical value — `~/.config` rather than
`~/.config/opencode` — so any future caller reaching for it by name would have
written the OpenCode config one directory too high.

Removed the wrapper and its now-unused import. A new test pins the canonical
resolver's contract and asserts the divergent re-export stays gone; the guard
was mutation-validated (re-adding the wrapper fails it).

check:dead-code: 409 = baseline, PASS.
cliRuntime/opencode suites: 51 pass, 0 fail. New guard: 3 pass, 0 fail.
lint / typecheck:core / file-size / complexity-ratchets / test-discovery: green.

changelog.d/fixes/basered-deadcode-opencode-config-dir.md

@@ -0,0 +1 @@
+- fix(cli): drop the orphaned `resolveOpencodeConfigDir` re-export from `cliRuntime` — it lost its last consumer in #10246 and diverged from the canonical resolver by one directory level (#9985)

src/shared/services/cliRuntime.ts

@@ -9,10 +9,7 @@ import { withSettingsFallback } from "./cliInstallFallback";
 import { GROK_BUILD_RUNTIME_ENTRY, AMP_RUNTIME_ENTRY } from "./cliRuntimeGrokBuild";
 import { isLocationTrusted, findKnownPathMatch } from "./cliRuntimeKnownPath";
 import { buildHealthcheckPath } from "./cliRuntimeHealthcheckPath";
-import {
-  resolveOpencodeConfigDir as resolveOpenCodeConfigDir,
-  resolveOpencodeConfigPath as resolveOpenCodeConfigPath,
-} from "./opencodeConfigPath";
+import { resolveOpencodeConfigPath as resolveOpenCodeConfigPath } from "./opencodeConfigPath";
 const VALID_RUNTIME_MODES = new Set(["auto", "host", "container"]);
 const FALSE_VALUES = new Set(["0", "false", "no", "off"]);
 
@@ -973,19 +970,6 @@ export const getCliConfigHome = () => {
   return normalized;
 };
 
-export const resolveOpencodeConfigDir = (
-  _platform = process.platform,
-  env: NodeJS.ProcessEnv = process.env,
-  homeDir = os.homedir()
-) => {
-  // #3330: OpenCode reads its config from XDG `~/.config/opencode/` on ALL
-  // platforms — including Windows, where it uses `%USERPROFILE%\.config`, NOT
-  // `%APPDATA%`. Writing to %APPDATA% on Windows put the file where OpenCode
-  // never looks, so dashboard-saved config silently had no effect. `_platform`
-  // is kept in the signature for call-site/test compatibility.
-  return path.dirname(resolveOpenCodeConfigDir(env, homeDir));
-};
-
 export const resolveOpencodeConfigPath = (
   _platform = process.platform,
   env: NodeJS.ProcessEnv = process.env,

tests/unit/opencode-config-dir-single-source.test.ts

@@ -0,0 +1,57 @@
+// Regression guard for the #10246 follow-up: `resolveOpencodeConfigDir` has exactly ONE
+// implementation, in `src/shared/services/opencodeConfigPath.ts`.
+//
+// #10246 moved the canonical resolvers into `opencodeConfigPath.ts` and left a thin wrapper
+// `resolveOpencodeConfigDir` behind in `cliRuntime.ts`. That wrapper lost its last consumer in
+// the same commit and became a dead export — which is what pushed the `check:dead-code` ratchet
+// to 410 (baseline 409) and made every PR on `release/v3.8.50` born red on that gate.
+//
+// Worse than the ratchet: the wrapper returned `path.dirname()` of the canonical value, i.e.
+// `~/.config` instead of `~/.config/opencode`. Two same-named exports with DIFFERENT return
+// values is a live foot-gun — a future caller importing from `cliRuntime` instead of
+// `opencodeConfigPath` would silently write the OpenCode config one directory too high.
+//
+// This test pins both halves: the canonical resolver's contract, and the absence of the
+// divergent re-export.
+
+import test from "node:test";
+import assert from "node:assert/strict";
+import path from "node:path";
+
+import { resolveOpencodeConfigDir } from "@/shared/services/opencodeConfigPath";
+import * as cliRuntime from "@/shared/services/cliRuntime";
+
+test("#10246 canonical resolveOpencodeConfigDir returns the XDG opencode directory", () => {
+  assert.equal(
+    resolveOpencodeConfigDir({ XDG_CONFIG_HOME: "/xdg" }, "/home/u"),
+    path.join("/xdg", "opencode")
+  );
+  // No XDG_CONFIG_HOME → `<home>/.config/opencode` on every platform (#3330: OpenCode reads
+  // XDG even on Windows, where it uses %USERPROFILE%\.config and never %APPDATA%).
+  assert.equal(
+    resolveOpencodeConfigDir({}, "/home/u"),
+    path.join("/home/u", ".config", "opencode")
+  );
+  // A blank/whitespace XDG_CONFIG_HOME must fall back, not produce a relative path.
+  assert.equal(
+    resolveOpencodeConfigDir({ XDG_CONFIG_HOME: "   " }, "/home/u"),
+    path.join("/home/u", ".config", "opencode")
+  );
+});
+
+test("#10246 cliRuntime does NOT re-export a divergent resolveOpencodeConfigDir", () => {
+  assert.equal(
+    (cliRuntime as Record<string, unknown>).resolveOpencodeConfigDir,
+    undefined,
+    "cliRuntime must not re-export resolveOpencodeConfigDir — the wrapper returned the PARENT " +
+      "directory (path.dirname of the canonical value), so importing it by name would write the " +
+      "OpenCode config one level too high. Import it from opencodeConfigPath instead."
+  );
+});
+
+test("#10246 cliRuntime still exposes the config PATH helpers it owns", () => {
+  // The path helpers legitimately stay on cliRuntime (they have live consumers) — this guard
+  // must not be read as "cliRuntime should stop exporting OpenCode helpers entirely".
+  assert.equal(typeof cliRuntime.resolveOpencodeConfigPath, "function");
+  assert.equal(typeof cliRuntime.getOpenCodeConfigPath, "function");
+});