chore: remove dead env vars from env-builder

Drop 5 fields with no codebase references:
- WS_MIN_PROTOCOL, WS_MAX_PROTOCOL (wa-guardian hardcodes these values)
- KEEP_ALIVE_INTERVAL (no usage; sync uses SYNC_INTERVAL)
- WORKSPACE_GIT_USER, WORKSPACE_GIT_NAME (unused)

159 → 154 fields.

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

env-builder.js

@@ -616,22 +616,6 @@ const FIELDS = [
     "type": "text",
     "ph": "https://..."
   },
-  {
-    "g": "Core",
-    "icon": "⚡",
-    "k": "WS_MIN_PROTOCOL",
-    "lbl": "Min WebSocket protocol",
-    "type": "number",
-    "ph": "1"
-  },
-  {
-    "g": "Core",
-    "icon": "⚡",
-    "k": "WS_MAX_PROTOCOL",
-    "lbl": "Max WebSocket protocol",
-    "type": "number",
-    "ph": "5"
-  },
   {
     "g": "Core",
     "icon": "⚡",
@@ -826,15 +810,6 @@ const FIELDS = [
     "ph": "huggingface",
     "common": 1
   },
-  {
-    "g": "Core",
-    "icon": "⚡",
-    "k": "KEEP_ALIVE_INTERVAL",
-    "lbl": "Keep-alive ping interval (seconds)",
-    "type": "number",
-    "ph": "300",
-    "common": 1
-  },
   {
     "g": "Core",
     "icon": "⚡",
@@ -931,22 +906,6 @@ const FIELDS = [
     "type": "text",
     "ph": "/home/node"
   },
-  {
-    "g": "Backup",
-    "icon": "💾",
-    "k": "WORKSPACE_GIT_USER",
-    "lbl": "Workspace git author email",
-    "type": "text",
-    "ph": "openclaw@example.com"
-  },
-  {
-    "g": "Backup",
-    "icon": "💾",
-    "k": "WORKSPACE_GIT_NAME",
-    "lbl": "Workspace git author name",
-    "type": "text",
-    "ph": "OpenClaw Bot"
-  },
   {
     "g": "Provider Keys",
     "icon": "🔑",