refactor(scripts): organize into build/dev/check/docs/i18n/ad-hoc subfolders

Reorganizes the 29 active scripts under scripts/ into purpose-driven
subfolders:

- scripts/build/    (11) — Build, install, publish, runtime env
- scripts/dev/      (13) — Dev servers, test runners, healthchecks
- scripts/check/    (10) — Lint/validation/coverage checks
- scripts/docs/      (2) — Docs index and provider reference generation
- scripts/i18n/     (+3) — Adds Python translation utilities (check/validate/autotranslate)
- scripts/ad-hoc/    (4) — One-shot maintenance utilities

Updates all references in package.json, electron/package.json,
.husky/pre-commit, .github/workflows/ci.yml, Dockerfile, src/,
tests/, scripts/ internal cross-imports, playwright.config.ts,
and English docs (CODEBASE_DOCUMENTATION, ENVIRONMENT, FEATURES,
RELEASE_CHECKLIST, COVERAGE_PLAN, ELECTRON_GUIDE, I18N, GEMINI).

Also patches scripts/build/pack-artifact-policy.ts so the npm pack
allowlist mirrors the new layout.

Validates with:
- npm run lint            (exit 0 — pre-existing minified-bundle errors only)
- npm run typecheck:core  (exit 0)
- npm run check:docs-all  (exit 0)
- unit tests for moved scripts (57 tests pass)

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

playwright.config.ts

@@ -34,7 +34,7 @@ export default defineConfig({
     },
   ],
   webServer: {
-    command: `${JSON.stringify(process.execPath)} scripts/run-next-playwright.mjs ${playwrightServerMode}`,
+    command: `${JSON.stringify(process.execPath)} scripts/dev/run-next-playwright.mjs ${playwrightServerMode}`,
     url: webServerReadyUrl,
     reuseExistingServer: !process.env.CI,
     timeout: Number.isFinite(playwrightWebServerTimeout) ? playwrightWebServerTimeout : 900_000,