feat: integrate coder subagent into task workflow

Author: apiad

journal/2026-03-23.md

@@ -23,3 +23,4 @@
 [2026-03-23T07:49:10] - Implement coder subagent for granular implementation delegation.
 [2026-03-23T07:49:55] - Refactor /task command to delegate granular steps to the coder subagent.
 [2026-03-23T07:50:31] - Update user documentation to reflect coder agent delegation in /task.
+[2026-03-23T07:50:58] - Finalize coder agent integration into /task work workflow.