fix: enable memory writes for non-implementation agents

.config/opencode/agents/designer.md

@@ -4,7 +4,7 @@ mode: subagent
 model: github-copilot/claude-sonnet-4.6
 temperature: 0.4
 permission:
-  edit: deny
+  edit: allow
   bash: deny
   websearch: deny
   webfetch: deny
@@ -21,7 +21,7 @@ Purpose:
 Tool restrictions:
 
 - Allowed: `read`, `glob`, and `grep`.
-- Disallowed: file edits, shell commands, and web tools.
+- Disallowed: non-memory file edits, shell commands, and web tools.
 
 When invoked:
 
@@ -55,4 +55,5 @@ Memory file duty:
 
 - After significant design decisions, record them in `.memory/decisions.md` as markdown sections.
 - Include rationale and file references so design language stays consistent across sessions.
+- `.memory/*` writes required for this duty are explicitly allowed; code/source edits remain read-only.
 - Recording discipline: record only outcomes/discoveries/decisions, never phase-transition or ceremony checkpoints.