feat(holiday-settings): implement organization holiday settings management

- Added SQL migration for creating organization holiday settings and state holidays tables with necessary constraints and indexes.
- Implemented API endpoints in AdminCenterController for retrieving and updating organization holiday settings.
- Updated admin-center API router to include routes for holiday settings management.
- Enhanced localization files to support new holiday settings UI elements in multiple languages.
- Improved holiday calendar component to display working days and integrate holiday settings.

worklenz-backend/database/migrations/20250728000000-add-organization-holiday-settings.sql

@@ -0,0 +1,63 @@
+-- Create organization holiday settings table
+CREATE TABLE IF NOT EXISTS organization_holiday_settings (
+    id              UUID                     DEFAULT uuid_generate_v4() NOT NULL,
+    organization_id UUID                                                NOT NULL,
+    country_code    CHAR(2),
+    state_code      TEXT,
+    auto_sync_holidays BOOLEAN               DEFAULT TRUE               NOT NULL,
+    created_at      TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP  NOT NULL,
+    updated_at      TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP  NOT NULL
+);
+
+ALTER TABLE organization_holiday_settings
+    ADD CONSTRAINT organization_holiday_settings_pk
+        PRIMARY KEY (id);
+
+ALTER TABLE organization_holiday_settings
+    ADD CONSTRAINT organization_holiday_settings_organization_id_fk
+        FOREIGN KEY (organization_id) REFERENCES organizations
+            ON DELETE CASCADE;
+
+ALTER TABLE organization_holiday_settings
+    ADD CONSTRAINT organization_holiday_settings_country_code_fk
+        FOREIGN KEY (country_code) REFERENCES countries(code)
+            ON DELETE SET NULL;
+
+-- Ensure one settings record per organization
+ALTER TABLE organization_holiday_settings
+    ADD CONSTRAINT organization_holiday_settings_organization_unique
+        UNIQUE (organization_id);
+
+-- Create index for better performance
+CREATE INDEX IF NOT EXISTS idx_organization_holiday_settings_organization_id ON organization_holiday_settings(organization_id);
+
+-- Add state holidays table for more granular holiday data
+CREATE TABLE IF NOT EXISTS state_holidays (
+    id          UUID                     DEFAULT uuid_generate_v4() NOT NULL,
+    country_code CHAR(2)                                            NOT NULL,
+    state_code  TEXT                                                NOT NULL,
+    name        TEXT                                                NOT NULL,
+    description TEXT,
+    date        DATE                                                NOT NULL,
+    is_recurring BOOLEAN                 DEFAULT TRUE               NOT NULL,
+    created_at  TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP  NOT NULL,
+    updated_at  TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP  NOT NULL
+);
+
+ALTER TABLE state_holidays
+    ADD CONSTRAINT state_holidays_pk
+        PRIMARY KEY (id);
+
+ALTER TABLE state_holidays
+    ADD CONSTRAINT state_holidays_country_code_fk
+        FOREIGN KEY (country_code) REFERENCES countries(code)
+            ON DELETE CASCADE;
+
+-- Add unique constraint to prevent duplicate holidays for the same state, name, and date
+ALTER TABLE state_holidays
+    ADD CONSTRAINT state_holidays_state_name_date_unique
+        UNIQUE (country_code, state_code, name, date);
+
+-- Create indexes for better performance
+CREATE INDEX IF NOT EXISTS idx_state_holidays_country_state ON state_holidays(country_code, state_code);
+CREATE INDEX IF NOT EXISTS idx_state_holidays_date ON state_holidays(date);