sprint: add design decisions section

sprints/agent-role-disambiguation.md

@@ -32,6 +32,27 @@ A single, unambiguous meaning for "agent" across the CLI, docs, and TOML. `disin
 ## Recommendation
 Worth it. This is a small, low-risk naming fix that unblocks cleaner UX for future agent management work (#557, #845-#847). The overload is already causing user-facing errors. Option A ("agent" = instance, rename role subcommand to `disinto role`) aligns with existing TOML (`[agents.X]`) and container naming (`agents-<name>`), minimizing total churn.
 
+## Design decisions
+
+<!-- Status: AWAITING ANSWERS — questions posted 2026-04-19 -->
+
+### Q1: New subcommand name
+What replaces `disinto agent {enable,disable,status}`?
+- A) `disinto role` — matches `AGENT_ROLES` naming, short, clear
+- B) `disinto service` — emphasizes polling-loop service aspect
+- C) `disinto module` — neutral, less intuitive for enable/disable
+
+### Q2: Internal variable rename scope
+Rename CLI surface only, or also internal identifiers?
+- A) CLI only — keep `AGENT_ROLES`, state files, function names unchanged
+- B) Full rename — `AGENT_ROLES`→`ACTIVE_ROLES`, state files, function names
+
+### Q3: Deprecation shim removal timing
+When does the old `disinto agent` alias get removed?
+- A) After #557 (agent-management-redesign) merges
+- B) Calendar-based: 30 days after merge
+- C) Never — keep alias permanently
+
 ## Sub-issues
 
 <!-- filer:begin -->