fix(explorer): address PR #486 review blockers + resolve conflict with main

Merge conflict resolution:
- Kept fix/graph-motion's conditional layout-stop (only in focused mode)
  to preserve live layout motion for derived graphs — the core intent of
  this PR.

Must-fix items resolved:

1. plugin.json — removed "hooks": "./hooks/hooks.json" (re-added by this
   branch, already removed in PR #489 on main as it is auto-loaded).
   Kept "agents": "./agents".

2. Double Louvain per render — added groupedViewAvailable useMemo in
   GraphWorkspace (deps: [graphVersion]) that runs community detection
   once. Passed result into resolveDisplayGraph and resolveDisplayStateSnapshot
   via new groupedViewAvailable option; both functions skip their internal
   computeGraphAnalyticsBase call when the value is pre-supplied.

3. graphVersion in displayState deps — removed graphVersion from the
   displayState memo dep array. displayState now depends on the stable
   boolean groupedViewAvailable, not on every ADD_NODE/ADD_EDGE tick,
   so Louvain no longer re-fires on every WebSocket update.

4. hideLabelsOnMove / hideEdgesOnMove flipped to true — intentional:
   suppressing labels and edges during pan reduces visual noise and is
   part of the flicker-reduction fix described in the PR.

Co-authored-by: ZohaibHassan16 <zohaibhassan1696@gmail.com>
Co-authored-by: KaifAhmad1 <kaifahmad087@gmail.com>

plugins/.claude-plugin/README.md

@@ -91,7 +91,8 @@ claude --plugin-dir ./plugins
 Or inside a session:
 
 ```bash
-/plugin install ./plugins
+/plugin marketplace add ./plugins
+/plugin install semantica@semantica-local
 ```
 
 Verify:

plugins/.claude-plugin/marketplace.json

@@ -1,5 +1,9 @@
 {
   "name": "semantica-local",
+  "owner": {
+    "name": "Hawksight AI",
+    "url": "https://github.com/Hawksight-AI/semantica"
+  },
   "plugins": [
     {
       "name": "semantica",

plugins/.claude-plugin/plugin.json

@@ -25,6 +25,5 @@
     "mcp"
   ],
   "skills": "./skills",
-  "agents": "./agents",
-  "hooks": "./hooks/hooks.json"
+  "agents": "./agents"
 }