fix(claude): disable attribution

Disable attribution in settings.json, add back the section about
attribution in CLAUDE.md due to claude sometimes ignoring the setting

.claude/CLAUDE.md

@@ -77,3 +77,7 @@ Scope may use slash-separated subscopes (`fix(parser/lexer)`, `feat(api/auth)`)
 Breaking changes: append `!` to the type or scope (`feat(api)!: ...`) and include a `BREAKING CHANGE:` footer when the change needs explanation.
 
 Don't retroactively rewrite committed history unless the user explicitly asks.
+
+### No Co-Authored-By Claude line
+
+Don't add `Co-Authored-By: Claude ... <noreply@anthropic.com>` (or any Claude co-author trailer) to commit messages. End the commit with the actual content. The user finds the trailer adds clutter without serving any audience.

.claude/settings.json

@@ -3,8 +3,12 @@
     "ENABLE_CLAUDEAI_MCP_SERVERS": "false"
   },
   "feedbackSurveyRate": 0,
-  "effortLevel": "xhigh",
+  "effortLevel": "high",
   "awaySummaryEnabled": false,
   "showClearContextOnPlanAccept": true,
-  "disableAutoMode": "disable"
+  "disableAutoMode": "disable",
+  "attribution": {
+    "commit": "",
+    "pr": ""
+  }
 }