## Problem
Tasks currently only expose a machine-friendly name field (e.g.
`task-python-debug-a1b2`), but this value is primarily an identifier
rather than a clean, descriptive label. We need a separate
display-friendly name for use in the UI.
This PR introduces a new `display_name` field and updates the task-name
generation flow. The Claude system prompt was updated to return valid
JSON with both `name` and `display_name`. The name generation logic
follows a fallback chain (Anthropic > prompt sanitization > random
fallback). To make task names more closely resemble their display names,
the legacy `task-` prefix has been removed. For context, PR
https://github.com/coder/coder/pull/20834 introduced a small Task icon
to the workspace list to help identify workspaces associated to tasks.
## Changes
- Database migration: Added `display_name` column to tasks table
- Updated system prompt to generate both task name and display name as
valid JSON
- Task name generation now follows a fallback chain: Anthropic > prompt
sanitization > random fallback
- Removed `task-` prefix from task names to allow more descriptive names
- Note: PR https://github.com/coder/coder/pull/20834 adds a Task icon to
workspaces in the workspace list to distinguish task-created workspaces
**Note:** UI changes will be addressed in a follow-up PR
Related to: https://github.com/coder/coder/issues/20801
This PR adds the backend implementation for modifying task prompts. Part
of https://github.com/coder/internal/issues/1084
## Changes
- New `UpdateTaskPrompt` database query to update task prompts
- New PATCH `/api/v2/tasks/{task}/prompt` endpoint
## Notes
This is part 1 of a 2-part PR stack. The frontend UI will be added in a
follow-up PR based on this branch
(https://github.com/coder/coder/pull/20812).
---
🤖 PR was written by Claude Sonnet 4.5 Thinking using [Coder
Mux](https://github.com/coder/cmux) and reviewed by a human 👩
* Adds a `GetTaskByOwnerIDAndName` query
* Updates `httpmw.TaskParam` to fall back to task name if no task by
UUID found.
* Updates the `TaskByIdentifier` used in `cli/` to use direct lookup instead of searching.
This change updates the `task_workspace_apps` table structure for
improved linking to workspace builds and adds queries to manage tasks
and a view to expose task status.
Updates coder/internal#948
Supersedes coder/coder#20212
Supersedes coder/coder#19773
Susana Ferreira