feat(FN-781): reposition AI-assisted creation controls adjacent to description field

- Move Plan and Subtask buttons next to the description input in QuickEntryBox, InlineCreateCard, and TaskForm
- Improve action button layout with consistent icon+label pattern and disabled states
- Add CSS styles for new action button group and description-adjacent controls
- Add regression tests for all three task creation surfaces ensuring buttons appear next to description
- Document the description-adjacent AI controls pattern in dashboard README

packages/dashboard/README.md

@@ -44,6 +44,7 @@ AI-guided interactive planning for creating well-specified tasks from high-level
 - **Task Detail Editing**: Edit task title and description directly in the task detail modal. Click the pencil icon in the modal header (available for Triage and Todo tasks) to enter edit mode.
 - **List View**: Alternative tabular view for tasks with sorting and filtering. The "Hide Done" toggle hides both Done and Archived tasks for an active-work-only view.
 - **Model Selection at Creation**: Choose executor and validator AI models while creating tasks from the board or list view, or leave them unset to use the global defaults. Quick-add model dropdowns in both the board triage column and the list view honor saved favorite providers and pinned models, matching the rest of the dashboard model UI.
+- **AI-Assisted Creation Controls**: Plan, Subtask, and Refine buttons appear directly below the description textarea in all task creation surfaces (quick entry box, inline create card, and task form modal). These description-adjacent controls make AI-assisted creation and refinement feel directly associated with the text being edited. Deps, Models, and Save actions remain in the expanded controls footer.
 - **Layered Model Dropdowns**: Shared model combobox menus render in a top-level portal attached to `document.body`, so they stay above board columns and scrollable modal content instead of being clipped behind surrounding dashboard surfaces.
 - **Bulk Model Editing**: Update AI model configuration for multiple tasks at once in the list view. Select tasks via checkboxes (archived tasks excluded), then use the "Bulk Edit Models" toolbar to apply executor and/or validator model changes to all selected tasks. Selection persists in localStorage across page reloads.
 - **Task Details**: View full task specifications, agent logs, and attachments. The Agent Log tab header shows the effective executor and validator model names resolved from task-level overrides or project/global settings fallbacks, matching the same resolution order the engine uses at runtime.