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": [

mem0-plugin/scripts/on_git_commit_capture.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+# Hook: PreToolUse (matcher: Bash)
+#
+# Detects `git commit` commands and fires on_pre_commit.py in the background
+# to capture staged changes as a mem0 memory. Never blocks the commit.
+#
+# Input:  JSON on stdin with tool_name, tool_input
+# Output: none (always exit 0)
+
+set -euo pipefail
+
+INPUT=$(cat)
+
+COMMAND=$(echo "$INPUT" | jq -r '.tool_input.command // ""' 2>/dev/null || echo "")
+
+if [ -z "$COMMAND" ]; then
+  exit 0
+fi
+
+case "$COMMAND" in
+  *"git commit"*|*"git merge"*|*"git rebase"*)
+    ;;
+  *)
+    exit 0
+    ;;
+esac
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+
+if [ ! -x "$SCRIPT_DIR/on_pre_commit.py" ] && [ ! -f "$SCRIPT_DIR/on_pre_commit.py" ]; then
+  exit 0
+fi
+
+API_KEY="${MEM0_API_KEY:-${CLAUDE_PLUGIN_OPTION_MEM0_API_KEY:-}}"
+if [ -z "$API_KEY" ]; then
+  exit 0
+fi
+
+git diff --cached --stat 2>/dev/null | python3 "$SCRIPT_DIR/on_pre_commit.py" &
+
+exit 0

mem0-plugin/skills/mem0-mcp/SKILL.md

@@ -276,14 +276,20 @@ add_memory(
 
 ### Access counter: track memory usage
 
-When you retrieve a memory via `search_memories` and **actually use it** in your response (i.e., it informed your answer or you cited it), increment its access counter by calling:
+When you retrieve a memory via `search_memories` and **actually use it** in your response (i.e., it informed your answer or you cited it), increment its access counter and update the last-accessed timestamp by calling:
 
 ```python
 # 1. Read current state
 mem = get_memory(memory_id=<id>)
 current_text = mem["content"]  # or mem["memory"], depending on response shape
+current_meta = mem.get("metadata", {})
 
-# 2. Update with access_count bump
+# 2. Bump access_count and set last_accessed
+import datetime
+current_meta["access_count"] = current_meta.get("access_count", 0) + 1
+current_meta["last_accessed"] = datetime.datetime.now(datetime.timezone.utc).isoformat()
+
+# 3. Update with preserved content
 update_memory(
     memory_id=<id>,
     data=current_text,  # preserve original text — required parameter
@@ -294,4 +300,4 @@ update_memory(
 
 **When to increment:** Only when you actually used the memory to answer. Don't bump on every search hit — that inflates counts for memories that were returned but irrelevant. Aim for 1-3 bumps per response at most.
 
-**Why:** Access counts feed into `/mem0:dream` pruning decisions. Memories that are never accessed after creation are candidates for cleanup. Frequently accessed memories are protected from pruning regardless of age.
+**Why:** `access_count` and `last_accessed` feed into `/mem0:dream` pruning decisions. Memories that are never accessed after creation are candidates for cleanup. Frequently accessed memories are protected from pruning regardless of age.