🗓️ feat: Add Special Variables for Prompts & Agents, Prompt UI Improvements (#7123)

* wip: Add Instructions component for agent configuration

* ✨ feat: Implement DropdownPopup for variable insertion in instructions

* refactor: Enhance variable handling by exporting specialVariables and updating Markdown components

* feat: Add special variable support for current date and user in Instructions component

* refactor: Update handleAddVariable to include localized label

* feat: replace special variables in instructions presets

* chore: update parameter type for user in getListAgents function

* refactor: integrate dayjs for date handling and move replaceSpecialVars function to data-provider

* feat: enhance replaceSpecialVars to include day number in current date format

* feat: integrate replaceSpecialVars for processing agent instructions

* feat: add support for current date & time in replaceSpecialVars function

* feat: add iso_datetime support in replaceSpecialVars function

* fix: enforce text parameter to be a required field in replaceSpecialVars function

* feat: add ISO datetime support in translation file

* fix: disable eslint warning for autoFocus in TextareaAutosize component

* feat: add VariablesDropdown component and integrate it into CreatePromptForm and PromptEditor; update translation for special variables

* fix: CategorySelector and related localizations

* fix: add z-index class to LanguageSTTDropdown for proper stacking context

* fix: add max-height and overflow styles to OGDialogContent in VariableDialog and PreviewPrompt components

* fix: update variable detection logic to exclude special variables and improve regex matching

* fix: improve accessibility text for actions menu in ChatGroupItem component

* fix: adjust max-width and height styles for dialog components and improve markdown rendering for light vs. dark, height/widths, etc.

* fix: remove commented-out code for better readability in PromptVariableGfm component

* fix: handle undefined input parameter in setParams function call

* fix: update variable label types to use TSpecialVarLabel for consistency

* fix: remove outdated information from special variables description in translation file

* fix: enhance unused i18next keys detection for special variable keys

* fix: update color classes for consistency/a11y in category and prompt variable components

* fix: update PromptVariableGfm component and special variable styles for consistency

* fix: improve variable highlighting logic in VariableForm component

* fix: update background color classes for consistency in VariableForm component

* fix: add missing ref parameter to Dialog component in OriginalDialog

* refactor: move navigate call for new conversation to after setConversation update

* refactor: move message query hook to client workspace; fix: handle edge case for navigation from finalHandler creating race condition for response message DB save

* chore: bump librechat-data-provider to 0.7.793

* ci: add unit tests for replaceSpecialVars function

* fix: implement getToolkitKey function for image_gen_oai toolkit filtering/including

* ci: enhance dayjs mock for consistent date/time values in tests

* fix: MCP stdio server fail to start when passing env property

* fix: use optional chaining for clientRef dereferencing in AskController and EditController
feat: add context to saveMessage call in streamResponse utility

* fix: only save error messages if the userMessageId was initialized

* refactor: add isNotAppendable check to disable inputs in ChatForm and useTextarea

* feat: enhance error handling in useEventHandlers and update conversation state in useNewConvo

* refactor: prepend underscore to conversationId in newConversation template

* feat: log aborted conversations with minimal messages and use consistent conversationId generation

---------

Co-authored-by: Olivier Schiavo <olivier.schiavo@wengo.com>
Co-authored-by: aka012 <aka012@neowiz.com>
Co-authored-by: jiasheng <jiashengguo@outlook.com>

client/src/locales/en/translation.json

@@ -542,6 +542,7 @@
   "com_ui_bulk_delete_error": "Failed to delete shared links",
   "com_ui_callback_url": "Callback URL",
   "com_ui_cancel": "Cancel",
+  "com_ui_category": "Category",
   "com_ui_chat": "Chat",
   "com_ui_chat_history": "Chat History",
   "com_ui_clear": "Clear",
@@ -616,7 +617,7 @@
   "com_ui_download_backup_tooltip": "Before you continue, download your backup codes. You will need them to regain access if you lose your authenticator device",
   "com_ui_download_error": "Error downloading file. The file may have been deleted.",
   "com_ui_drag_drop": "something needs to go here. was empty",
-  "com_ui_dropdown_variables": "Dropdown variables:",
+  "com_ui_dropdown_variables": "Dropdown variables",
   "com_ui_dropdown_variables_info": "Create custom dropdown menus for your prompts: `{{variable_name:option1|option2|option3}}`",
   "com_ui_duplicate": "Duplicate",
   "com_ui_duplication_error": "There was an error duplicating the conversation",
@@ -806,9 +807,14 @@
   "com_ui_sign_in_to_domain": "Sign-in to {{0}}",
   "com_ui_simple": "Simple",
   "com_ui_size": "Size",
-  "com_ui_special_variables": "Special variables:",
-  "com_ui_special_variables_info": "Use `{{current_date}}` for the current date, and `{{current_user}}` for your given account name.",
+  "com_ui_special_var_current_date": "Current Date",
+  "com_ui_special_var_current_datetime": "Current Date & Time",
+  "com_ui_special_var_iso_datetime": "UTC ISO Datetime",
+  "com_ui_special_var_current_user": "Current User",
+  "com_ui_special_variables": "Special variables",
+  "com_ui_special_variables_more_info": "You can select special variables from the dropdown: `{{current_date}}` (today's date and day of week), `{{current_datetime}}` (local date and time), `{{utc_iso_datetime}}` (UTC ISO datetime), and `{{current_user}}` (your account name).",
   "com_ui_speech_while_submitting": "Can't submit speech while a response is being generated",
+  "com_ui_sr_actions_menu": "Open actions menu for \"{{0}}\"",
   "com_ui_stop": "Stop",
   "com_ui_storage": "Storage",
   "com_ui_submit": "Submit",
@@ -859,4 +865,4 @@
   "com_ui_zoom": "Zoom",
   "com_user_message": "You",
   "com_warning_resubmit_unsupported": "Resubmitting the AI message is not supported for this endpoint."
-}
+}