chore(importer): fix lint errors flagged by CI

  - cutover-dry-run.ts: drop the redundant `= 0` assignment that the
    try/catch immediately overrides (no-useless-assignment)
  - importer.ts: convert `(_msg: string) => {}` to `(): void => {}`
    (no-unused-vars); add `cause` to the error rethrown from
    `ensureGitRepo` (preserve-caught-error)
  - tests/import-laddr.test.ts: drop unused RawPersonSchema /
    RawProjectSchema imports; rename `_` loop variable to `_row` with an
    explicit eslint-disable so the no-unused-vars rule is silenced

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: themightychris

apps/api/scripts/cutover-dry-run.ts

@@ -213,7 +213,7 @@ export async function runDryRun(opts: DryRunOptions): Promise<DryRunReport> {
   // but flag them in the report so they're visible.
   const countDiffs: CountDiff[] = [];
   for (const { path, sheet } of ENDPOINT_TO_SHEET) {
-    let sourceTotal = 0;
+    let sourceTotal: number;
     try {
       sourceTotal = await fetchTotal(path, {
         host: opts.sourceHost,

apps/api/scripts/import-laddr/importer.ts

@@ -159,7 +159,7 @@ export async function importLaddrFromJson(opts: ImportOptions): Promise<ImportRe
   const runAt = opts.now ?? new Date().toISOString();
   const branch = opts.branch ?? 'legacy-import';
   const initialParent = opts.initialParent ?? 'origin/empty';
-  const log = opts.verbose ? (msg: string) => console.log(msg) : (_msg: string) => {};
+  const log = opts.verbose ? (msg: string) => console.log(msg) : (): void => {};
 
   const warningsList: string[] = [];
   const warnings: Warnings = {
@@ -646,6 +646,7 @@ async function ensureGitRepo(repo: string): Promise<void> {
   } catch (err) {
     throw new Error(
       `[import-laddr] ${repo} is not a git working directory: ${describe(err)}`,
+      { cause: err },
     );
   }
 }

apps/api/tests/import-laddr.test.ts

@@ -17,8 +17,6 @@ import { describe, expect, it } from 'vitest';
 import { importLaddrFromJson } from '../scripts/import-laddr/importer.js';
 import {
   fetchAllPages,
-  RawPersonSchema,
-  RawProjectSchema,
   RawTagSchema,
   type RawPerson,
   type RawProject,
@@ -168,7 +166,8 @@ describe('fetchAllPages', () => {
       { host: 'example.test', pageSize: 2, delayMs: 0, fetchImpl: makeFetch(routes) },
     );
     await expect((async () => {
-      for await (const _ of it_) {
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      for await (const _row of it_) {
         // intentionally empty
       }
     })()).rejects.toThrow();