4.88v

1. Notable changes since 4.87v
   - Offline reasons: introduced configurable offline reasons with the new `lh_abstract_offline_reason` model and CRUD interface; operators can select a reason (e.g. "Lunch", "Meeting") with an icon when setting themselves offline, persisted on `lh_users` and `lh_users_online_session`; offline reasons are displayed in online-hours statistics and user-box menus with a redesigned status control layout; a new `offlinereasons` permission controls access to this feature.
   - Forms module overhaul: added comprehensive search and filtering for collected forms, including department filter, chat operator filter, date range, creator filter, and chat-time search; introduced field change tracking for internal forms — when an operator edits a previously submitted form, field history (old/new values and modifier) is logged; added translation support and improved template variable management for forms; refactored module navigation with proper permission checks and removed deprecated index page; enhanced embed code generation with access control; clearing chat attributes when deleting collected form data now properly reverts associated chat variables and additional data entries.
   - Bot enhancements: added secondary translations group support for bots, allowing an optional second translations group in bot configuration with proper validation and item retrieval from both groups; added "Trigger on bot skip" option to proactive invitations, executing triggers when a visitor skips the bot; fixed missing `last_msg_id` update after sending invitation messages.
   - Security hardening: refactored CAPTCHA to use browser fingerprinting (combining multiple HTTP headers) and SHA-256 hashing for improved security across chat validation, FAQ, voting, and widget modules; added more detailed CAPTCHA error messages; added `ignoreactivityglobal` permission allowing individual users to opt out of activity tracking; replaced redirect with proper permission-denied page for abstract list views; added `from_address` emptiness check to prevent mailbox sync failures on null sender addresses.
   - Performance and stability: improved MySQL reconnect logic by removing stale connection caching and properly resetting reconnect counters; guarded compiled config caching behind database connection checks to prevent warmup/CLI failures; wrapped `setinactive.php` in a transaction with row locking and added `syncAndLock()` to `setoffline.php` to prevent race conditions on online status updates; added `resetSession()` methods across persistent session helpers for clearing cached ezcPersistentSession instances; added server info panel showing address, name, port, software, and uptime in audit configuration.
   - Admin custom fields: refactored processing to prevent duplicate field values by moving admin fields after JS variable processing and tracking processed identifiers; admin custom fields with `uempty` show condition are now hidden from returning visitors who already have a non-default nickname set; added support for original author re-modifying fields.
   - UI and UX: updated Bootstrap badge classes from v4 to v5 (`badge-*` to `bg-*`) across GroupChat, operators template, and mailing import templates; improved assignment configuration UX; translated theme before survey rendering in `fill` and `fillwidget` modules; adjusted naming for less confusion; added server and user timestamps to audit config and login pages.
   - Miscellaneous: fixed #2400; added support for BOM UTF format files; added avatar caching; added search attribute support for extensions; fixed installer config validation with clearer error messages; refactored `addmsgadmin.php` input validation to handle missing input gracefully; handled edge database reconnect cases; fixed CAPTCHA time drift validation; ensured dynamic property support.

2. Summary
   - This release introduces a major new feature — configurable offline reasons — allowing operators to specify why they are offline with visual indicators across the UI and statistics.
   - The forms module receives a comprehensive upgrade with advanced search/filtering, field change tracking, translation support, and improved permission handling.
   - Bot capabilities expand with secondary translations groups and trigger-on-skip functionality.
   - Security is strengthened through CAPTCHA fingerprinting, SHA-256 hashing, and multiple permission/validation improvements.
   - Performance and stability are enhanced with improved MySQL reconnect handling, race condition fixes, and guarded config caching.

execute doc/update_db/update_354.sql for update

4.87v

1. Notable changes since 4.86v
   - Performance and caching: improved dashboard online-operator retrieval with better user-data fetching and caching; prefill departments cache for faster lookups; ensure static cache version is respected across the application even without extensions; optimized chat archive range fetching with cached range checks before database queries, plus methods for matching ranges and verifying chat existence in archives with proper overlap handling.
   - Performance statistics: added total offline time tracking to agent statistics widgets with new help modal explaining offline time; updated translations, tooltip descriptions, and column spans in the agent statistics table for improved clarity; enhanced operator performance access checks to include write permissions.
   - Webhooks and events: added support for unread-message flow in webhook conditions with checkboxes enabling unread-message handling for admin messages; updated backend logic across message types and enhanced chat update logic to reflect unread-message states for operators; dropped redundant `chat_id` dependency.
   - Mail conversation: enhanced Mail Conversation API and search functionality; added proper API error handling.
   - Bot: refactored bot condition evaluation to streamline logic in action buttons and text triggers; updated type casting for threshold values in bot action commands.
   - ChatML export: significantly improved ChatML export logic and configuration; fixed properties in exported ChatML; resolved edge cases and format inconsistencies; export script improvements.
   - REST API: added support for REST file captions with configurable skip extensions (#2394).
   - Template and variable system: added support for `{item:path}` syntax enabling nested attribute extraction in output formatting; host values now support replaceable variables; fixed item replacement logic for proper handling of non-string values in templates.
   - Debug and diagnostics: improved debug invitation logic with detailed checks for message-seen status, timeout handling, and reshown conditions; enhanced debug message view UX, API scroll behavior, spacing, and col-span variables; logs now include exception URLs; added logging for changed user groups.
   - Widget and online visitors: dedicated online visitors page now always shows visitors even when the widget is minimized.
   - Bug fixes: fixed #2391 and #2395; updated checkbox labels for clarity; trimmed whitespace from messages before saving for data consistency; updated message retrieval limits across components for better performance and consistency; avoided throwing SQL errors in edge cases.

2. Summary
   - This release strengthens performance through improved caching strategies (departments, archive ranges, static cache, operator data) and extends performance statistics with offline-time tracking.
   - Webhook conditions gain unread-message-flow support, bot condition evaluation is streamlined, and the ChatML export pipeline receives a comprehensive overhaul.
   - Template variables now support nested `{item:path}` extraction, debug/invitation diagnostics are enhanced, and several stability issues are resolved.

execute doc/update_db/update_353.sql for update

4.86v

1. Notable changes since 4.85v
   - Performance statistics dashboard widgets: added new `dep_performance` and `op_performance` dashboard widgets that display real-time aggregated statistics for departments and operators respectively; widgets support configurable columns (chats received, chats answered, wait time, first/average response time, thumbs up/down, online/offline time) with configurable position and update intervals; new settings UI under Statistics for both department and operator performance configuration.
   - Performance stats cron aggregator: new cron job (`cron/stats/performance`) aggregates department and operator performance data into the new `lh_abstract_performance` table; supports forced regeneration via `-p force`; configurable update interval and day range; cron respects sql_mode and local timezone settings.
   - New `Performance` and `PerformanceWidgets` models: `Performance` model stores/retrieves serialized performance snapshots; `PerformanceWidgets` provides formatted data for dashboard sync, including per-department and per-operator stats with access-control filtering.
   - Security and authentication hardening: improved password verification logic in REST API validator; added constant-time response delay in forgot-password flow to mitigate timing attacks; updated hashing methods for login and password update flows; implemented expired hash cleanup (deleteExpiredHashes) called from setRemindHash, remindpassword, and forgotpassword modules; removed LDAP authentication components; updated autologin with nonce support and improved hash validation; masked error messages for users without access to unhidden emails in send and reply APIs.
   - Bot and event system: enhanced chat variable update handling and event dispatching; ignored default trigger message when a trigger is started manually; added support for invisible arguments in bot triggers; added event dispatch for transfer-to-human action; added event argument for custom is-online status checks.
   - Editor and operator UI: added switch-editor option in active chat tab and a new permission for operators to toggle between new and old editors; added icons and colors to the transfer window; increased subject modal window width; fixed form loading scroll event; avoided null being displayed before a chat starts.
   - Export and reports: enhanced export functionality with ChatML support and UI improvements; fixed compatibility with non-strict sql_mode for certain reports.
   - Bug fixes: fixed matching rule search; minor fixes including string conversion and typo corrections.

2. Summary
   - This release introduces a new real-time performance dashboard with configurable department and operator widgets backed by a cron aggregator and a dedicated `lh_abstract_performance` table.
   - Security is hardened across authentication flows: stronger hashing, timing-safe responses, expired hash cleanup, autologin nonce support, and LDAP removal.
   - Operator productivity is improved with a switchable editor, richer transfer UI, and expanded bot/event capabilities. Export and report compatibility are also addressed.

execute doc/update_db/update_352.sql for update

4.85v

1. Notable changes since 4.84v
   - Security and access control: tightened chat operation permissions by requiring proper read/write access checks; additional permission hardening was applied across related flows.
   - CSP and policy handling: completed CSP parser integration and follow-up fixes, including policy exposure hardening and parser/library alignment.
   - Voice messaging and widget UX: improved voice-message flow and UX, updated voice app behavior, kept cursor focus on desktop, and added a widget-theme option to disable voice messages.
   - Translation workflow: improved automatic translation reliability, added DeepL model/formality options, enhanced metadata/error handling, and refined start/stop and old-message translation flows.
   - Analytics and timing metrics: improved chat duration/response-time calculations, participant timing accounting, and operator duration output in reports.
   - REST API and diagnostics: added optional custom REST API messages, improved exception visibility/traceback details, and enabled direct log viewing from back office.
   - Invitations and online-hours logic: enhanced invitation alias/profile handling and improved overlapping online-hours period calculations.
   - UI/translations/dependencies: updated translations, refreshed JS dependencies (including html-react-parser migration), and applied multiple package/security updates.
   - Misc fixes: delivered issue-specific fixes and regressions cleanup (including #2378, #2379, #2382), plus release workflow updates.

2. Summary
   - This release focuses on security hardening, CSP maturity, and operator productivity, while also improving voice messaging UX and translation automation quality.
   - It also improves chat/mail timing metrics and diagnostics, with additional stability updates across UI, dependencies, and release automation.

No new DB migration script required for this release.

4.84v

1. Notable changes since 4.83v
   - REST API and bot workflow: improved REST API trigger execution and request body handling with attachment support; added skipped-body debug preview; enhanced chat locking behavior for streaming and chunked responses while preserving typing indicators.
   - Widget and UI: expanded widget theme customization options (including color controls), applied theme colors to offline form, improved message delivery indicator styling, fixed height adjustments and zoom/icon interaction issues, and added support for custom nick from admin themes.
   - Notifications and operator workflow: added assignment notification preferences (assigned pending chats vs all pending chats), quick action for auto-assignment, and persistent disabling of mobile notifications.
   - Chat filters and analytics: added participant filters to chat search, improved filters and restored pagination behavior, added participant-aware export enhancements, and introduced average chat duration by agent/participant.
   - File validation and security hardening: expanded MIME type handling for common file types and strengthened uploaded file verification (including file preview upload flow).
   - Translation and UX polish: improved translation error handling and transaction flow, added operator notice for active chat translation state, and updated translations across modules.
   - Core/codebase maintenance: added new tables and schema updates, improved error/log reporting and timing diagnostics (render and DB connection timing), and modernized PHP code style in core files.

2. Summary
   - This release focuses on reliability and operator experience: stronger REST API/bot handling, better widget customization and messaging UX, richer notification controls, and improved chat search/export analytics.
   - It also includes security-oriented file validation improvements, translation workflow refinements, and core maintenance updates for better observability and long-term stability.

execute doc/update_db/update_351.sql for update

4.83v

1. Notable changes since 4.82v
   - Chat list sorting: added sort options for highest and lowest message count in chat lists; a validation warning is shown when sorting by message count without a date range of 31 days or less.
   - Webhooks: debug mode support added to `processEvent` in both chat and mail conversation continuous webhook classes; new validation conditions `notempty` and `in_list`; improved error handling and logging; webhook form updated with chat ID testing and improved button styling; test pattern module enhanced with webhook ID validation.
   - Dropdown: "Select all" and "Unselect all" buttons added to multi-select dropdowns across the back-office; dropdown plugin and render helper updated accordingly.
   - Subject filter: subject filter conditions added to the chat list search panel and mail conversation search panel; department user dep logic enhanced.
   - Widget: bumped to version 272; improved `screenAttributesUpdate` height/width calculations for better responsiveness across screen sizes; wrapper now passes its version to the API; fixed proper termination in wrapper source.
   - Canned messages: fixed auto-uppercase breaking text input in the new rich-text editor (LHCEditor).
   - REST API: fixed authentication validator regression.
   - Chat core: added support for dashes in chat handling logic.
   - Templates: minor fixes in chat lists template and survey fill-widget template.

2. Summary
   - This release improves chat list usability with message count sorting, strengthens webhook debugging with debug mode and new validation conditions, and enhances multi-select dropdowns with select-all/unselect-all controls.
   - Widget responsiveness and wrapper version reporting are improved; canned message auto-uppercase and REST API auth issues are resolved.

execute doc/update_db/update_350.sql for update