fix(mem0-plugin): wire pre-commit capture hook, add Setup hook, fix access counters

- Add PreToolUse(Bash) hook: detects `git commit` commands, fires
  on_pre_commit.py in background to capture staged changes as memory
- Add Setup(init|maintenance) hook: installs mem0ai SDK on first plugin
  install via ensure_deps.sh (120s timeout for slow networks)
- Add on_git_commit_capture.sh wrapper: reads tool input JSON, matches
  git commit/merge/rebase, runs capture script fire-and-forget
- Fix #24: add metadata.last_accessed ISO timestamp to access counter
  instructions in mem0-mcp/SKILL.md alongside existing access_count

mem0-plugin/hooks/hooks.json

@@ -1,5 +1,18 @@
 {
   "hooks": {
+    "Setup": [
+      {
+        "matcher": "init|maintenance",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "${CLAUDE_PLUGIN_ROOT}/scripts/ensure_deps.sh",
+            "statusMessage": "Installing mem0 SDK...",
+            "timeout": 120
+          }
+        ]
+      }
+    ],
     "SessionStart": [
       {
         "hooks": [
@@ -31,6 +44,16 @@
             "command": "${CLAUDE_PLUGIN_ROOT}/scripts/block_memory_write.sh"
           }
         ]
+      },
+      {
+        "matcher": "Bash",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "${CLAUDE_PLUGIN_ROOT}/scripts/on_git_commit_capture.sh",
+            "timeout": 5
+          }
+        ]
       }
     ],
     "PostToolUse": [