refactor(vscode): Hide Memory and Research Synthesis panels

Removed "Memory (Beta)" and "Research Synthesis" dropdown panels from
the sidebar, keeping only the "Dashboard" panel visible for cleaner UX.

Users can still access memory features through commands if needed.

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

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

Author: 2 people

vscode-extension/package.json

@@ -221,16 +221,6 @@
           "type": "webview",
           "id": "empathy-dashboard",
           "name": "Dashboard"
-        },
-        {
-          "type": "webview",
-          "id": "empathy-memory",
-          "name": "Memory (Beta)"
-        },
-        {
-          "type": "webview",
-          "id": "research-synthesis",
-          "name": "Research Synthesis"
         }
       ]
     },