praxis: remove PreToolUse EnterPlanMode hook that caused plan mode failures

The hook that checked .light/sessions/ for research artifacts before
entering plan mode was intermittently failing, disrupting the
research → plan → implement flow.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ericjohnolson

plugins/praxis/hooks/hooks.json

@@ -1,16 +1,6 @@
 {
   "description": "LightFactory Praxis plugin hooks for plan-mode-native RPI workflow",
   "hooks": {
-    "PreToolUse": [
-      {
-        "matcher": "EnterPlanMode",
-        "hooks": [
-          {
-            "type": "prompt",
-            "prompt": "Check .light/sessions/ for any research artifact (*-research.md). If one exists and is relevant to the current task, mention it so the planning phase can build on it."
-          }
-        ]
-      }
-    ]
+    "PreToolUse": []
   }
 }