fix(crew): improve Claude detection and add auto-prime hook

- IsClaudeRunning: remove UI marker check that caused false positives
  when Claude output remained in scrollback after exit
- Add .claude/settings.json with SessionStart hook for gt prime

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.claude/settings.json

@@ -0,0 +1,15 @@
+{
+  "hooks": {
+    "SessionStart": [
+      {
+        "matcher": "",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "gt prime"
+          }
+        ]
+      }
+    ]
+  }
+}