Fix agent auth during shutdown scripts (#19467) #1249

Repo: coder/coder

Scope: Fix agent token validation so run_on_stop scripts can make authenticated API calls.

Problem: The agent auth query joins with the latest build. When a stop build is created, the agent from the previous start build fails authorization before shutdown scripts complete.

Changes:

• Modify agent token validation query in coderd/database/queries/workspaceagents.sql
• Ensure agent token remains valid during the shutdown window
• Add tests for shutdown script auth scenarios

Files:

• coderd/database/queries/workspaceagents.sql (L285-325)
• coderd/httpmw/workspaceagent.go
• Tests

Acceptance criteria:

• Agent token valid during run_on_stop script execution
• Shutdown scripts can POST to coderd endpoints
• No regression in normal agent auth flows
• Test coverage for shutdown auth scenario

Dependencies: None (prerequisite for others)

References:

• Bug: Agent loses authorization before run_on_stop script completes coder#19467