refactor(mem0-plugin): improve hook scripts, config parsing, and skill definitions

Update git commit capture with better error handling, enhance user prompt hook,
extend config parser capabilities, and refine skill docs for dream, health,
mcp, pin, and stats skills.

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

@@ -63,6 +63,18 @@ Print a compact dashboard with an ASCII histogram for category distribution:
     user_preference   ██░░░░░░░░░░░░░░  3
     session_state     █░░░░░░░░░░░░░░░  2
 
+  By age:
+    < 7 days          ████████████████  5
+    7–30 days         ██████████░░░░░░ 12
+    30–90 days        ████░░░░░░░░░░░░ 10
+    > 90 days         ██░░░░░░░░░░░░░░  8
+
+  By access count:
+    Never accessed    ████████████████ 18
+    1–5 accesses      ████████░░░░░░░░ 10
+    6–20 accesses     ████░░░░░░░░░░░░  4
+    20+ accesses      █░░░░░░░░░░░░░░░  3
+
   Oldest memory:     <date>
   Newest memory:     <date>
 
@@ -78,5 +90,7 @@ Print a compact dashboard with an ASCII histogram for category distribution:
 - Use `█` for filled and `░` for empty. Right-align the count number.
 - Sort categories by count descending. Omit categories with 0 memories.
 - If only 1-2 categories exist, still show the histogram — it provides visual context.
+- **Age buckets:** Compute from `created_at`. Buckets: <7d, 7–30d, 30–90d, >90d.
+- **Access count buckets:** Read `metadata.access_count` (default 0 if absent). Buckets: 0, 1–5, 6–20, 20+.
 
 Skip any section with zero data.