feat: country-neutral work policies and release 1.4.0

[patrickschiller]

Summary

OpenClockwork currently assumes German holidays, automatic break deductions, and a Europe/Berlin deployment timezone. This release makes those policies explicit and configurable for organisations worldwide while preserving existing installations through a forward migration.

Linked issue

None; requested project internationalisation and release 1.4.0.

Changes

• Add optional employee holiday calendars and custom dates, editable schedule break rules, and time-entry policy snapshots. New employees and schedules use neutral defaults; existing calendars, allowances, and deductions are preserved.
• Use explicit installation/terminal timezones with UTC defaults, browser-language detection, regional formatting, and translated UI labels. Correct date-only leave displays and upcoming-leave filtering.
• Keep the deprecated bundesland API alias, regenerate OpenAPI and the web client, and document nullable responses and validation of conflicting selections.
• Add a prominent roadmap covering complete Solo mode, customer invoices, CAUR usage accounting, and combined human/agent billing. These remain planned features.
• Align public documentation and all release metadata with 1.4.0. No new dependencies.

How was this tested?

• pnpm nx run-many -t lint,typecheck,test,build -p api,web,shared,api-e2e,web-e2e --configuration=ci: passed; 88 shared and 94 web tests.
• pnpm nx e2e api-e2e: 147 tests passed against isolated PostgreSQL.
• Forward migration smoke test from 1.3.0 verified existing calendars, deductions, time entries, and terminal data.
• Docker API/web builds and local PostgreSQL/API/web/HTTPS gateway health checks passed; browser login and new calendar/break controls verified.
• Regenerated API contract, Nx formatting, git diff --check, and RELEASE_TAG=v1.4.0 pnpm release:verify-tag passed.

Release notes

Country-neutral work policies and regional UI defaults, with migration of existing installations. Full curated notes are in RELEASE_NOTES.md; Solo mode, invoices, and CAUR billing are covered in ROADMAP.md as planned work.

Upgrade impact

• Database migration: 20260907120000_international_work_policies; atomic migration preserves legacy policies and historical deductions.
• Compatibility: bundesland can now be null. New records no longer assume German calendars or automatic breaks; setup must explicitly configure the intended policy and leave allowance.
• Manual operator action: back up database/attachments, retain volume names, and explicitly retain the existing TZ before upgrading. Deploy API 1.4.0 before web 1.4.0. See UPGRADING.md.

Checklist

• All commits have DCO sign-off.
• Local lint, typecheck, tests, and builds pass.
• Behaviour changes have focused regression coverage.
• Release notes and upgrade impact are documented.
• Existing Prisma migrations are unchanged; schema changes use a new migration.
• Existing domain tests were reviewed; no base-instructions.md exists in this checkout.
• No new third-party dependencies.