Tasks: CLI send auto-resumes paused tasks

[mafredri]

Repo: coder/coder

Scope: Modify coder tasks send to automatically resume paused tasks before delivering message.

Changes:

• Attempt to send message to task
• If 409 response (task paused):
  • Print "Task is paused. Resuming (this may take a moment)..."
  • Call POST /tasks/{task}/resume endpoint
  • Poll task status until active or build fails (see Polling logic below)
  • Show build progress via cliui.WorkspaceBuild()
  • Retry send when task is active
  • Print "Input sent." on success

Polling logic:

• Poll task status every 5 seconds
• Exit loop when task.Status == "active" (workspace running, agent ready, AgentAPI responding)
• Exit loop on terminal build failure (job status is failed/canceled)

Error handling:

• 409 on send, resume build fails: Print build failure details, exit with code 1
• 409 on send, resume succeeds, retry send fails: Print send error (network/AgentAPI issue), exit with code 1
• Non-409 send error: Print error, exit with code 1 (no resume attempted)

Files:

• cli/task.go
• cli/task_test.go

Acceptance criteria:

• Send to active task works normally (no change in behavior)
• Send to paused task receives 409, triggers resume, waits for active, retries send
• Build progress displayed during resume via cliui.WorkspaceBuild()
• Polling exits when task.Status == "active" and send succeeds
• Terminal build failure stops polling and shows build error
• Retry send failure after successful resume shows send error (not resume error)
• All error messages are actionable and clear

Dependencies:

• Tasks: Resume endpoint #1262
• Tasks: API /send returns 409 when paused #1265

References:

• PRD: Start/Pause/Resume the Task Workspace
• RFC: Tasks: Start/Pause/Resume Lifecycle: CLI, Auto-Resume Option A