Closes#580.
Slovenian community contribution from @blazmaric (filed as an issue
with attached files rather than as a PR — files inlined here unchanged
except for the migration number).
## Changes
- **`frontend/src/i18n/locales/sl.json`** — full Slovenian UI
translations. Covers every top-level key present in `en.json` as
of pre-CRM beta. The new CRM-module keys (`bills`,
`businessProfile`, `calendar`, `contracts`, `crm`, `crmDev`,
`crmSettings`, `dealLineage`, `eventReminderOverride`,
`hoursLogging`) are not yet translated and will fall back to
English — same posture as FR / NL / PT / RU / ES currently have
for the CRM module (see PR #555 description).
- **`frontend/src/components/common/LanguageSelector.tsx`** — adds
`SLFlag` SVG component + registers `{ code: 'sl', name:
'Slovenščina', Flag: SLFlag }` in `SUPPORTED_LANGUAGES`. Frontend
i18n auto-discovers locale files via `import.meta.glob` so no
separate config registration is needed.
- **`backend/migrations/core/108_seed_sl_email_template_translations.js`** —
contribution-author's `107_*` filename renumbered to `108_` to
avoid collision with `107_crm_consolidated.js` that landed on beta
in the meantime. Idempotent insert via (template_id, language)
uniqueness check — re-runnable, never overwrites admin edits.
Covers 17 templates: admin invitation / password reset, archive
complete, backup completed / failed, customer gallery assigned,
customer invitation / password reset, database backup completed /
failed, expiration warning, gallery created / expired, restore
completed / failed, version update available / test.
- **`backend/src/services/emailProcessor.js`** — adds `.si → sl` to
the email-domain → language inference map, matching the pattern
for every other supported locale. A customer with `@example.si`
now gets Slovenian emails automatically without needing to set
their preferred_language explicitly.
## Out of scope (consistent with existing locales)
- CRM email templates (quote_sent, invoice_sent, contract_sent, etc.,
seeded at boot by `crmEmailTemplates.ensureCrmEmailTemplatesSeeded`)
will fall back to English for Slovenian customers — those seeders
only emit EN + DE rows today across every locale.
- CRM UI strings under the missing top-level keys listed above will
fall back to English.
Both gaps mirror the existing FR / NL / PT / RU / ES situation.