locale-reachable: default to this repo, not one author's worktree

Fourth instance of one pattern in this flight, after check-zone-census,
check-share-policy and check-poster-prints: a new internal/ gate hardcodes
its author's worktree (/home/.../wt-packet) as the REPO fallback, and
check:no-abs-paths -- which runs inside build:unlocked -- turns red for
every other builder on the next merge.

DOXA_REPO still wins and is untouched; only the default becomes portable,
via the idiom check-no-absolute-paths.mjs prints in its own failure text.
Verified both ways: check:no-abs-paths 0, check:locale-reachable 0 on the
derived default.

Four occurrences is a template problem, not four accidents.

internal/check-locale-reachable.mjs

@@ -15,10 +15,14 @@
 //      path (Polylang on WordPress) keeps working. If someone later makes the pages
 //      lang-less, the URL path alone would silently become the only way in.
 import { readFileSync, readdirSync, existsSync } from 'node:fs'
-import { resolve, join } from 'node:path'
+import { resolve, join, dirname } from 'node:path'
 
 const REPO = process.env.DOXA_REPO
-  || resolve('/home/lk10x/Workspace/eco-dx/root-doxa-maps/wt-packet')
+  // FOURTH instance of this pattern in one flight (check-zone-census, check-share-policy,
+  // check-poster-prints, now this). DOXA_REPO still wins; only the default becomes portable,
+  // per the idiom check-no-absolute-paths.mjs prints in its own failure text. A gate that
+  // hardcodes its author's worktree turns build:unlocked red for every other builder.
+  || resolve(dirname(fileURLToPath(import.meta.url)), '..')
 const src = readFileSync(join(REPO, 'library/i18n/index.js'), 'utf8')
 
 const SUPPORTED = (src.match(/SUPPORTED_LOCALES = \[([^\]]*)\]/) || [])[1]