fix(mem0-plugin): remove noisy session-state dumps, match openclaw pattern

- Remove all background REST API transcript dumps (on_pre_compact.py,
  capture_compact_summary.py, on_pre_commit.py calls) that were creating
  noisy session_state and commit_context memories automatically
- Rewrite pre-compaction prompt to extract individual durable facts
  (decisions, learnings, anti-patterns) instead of session summary blobs
- Agent now decides what to store, matching openclaw's triage pattern:
  "Most sessions produce zero memory operations. That is correct."
- Fix auto_import.py to search git repo root for CLAUDE.md/AGENTS.md
  (was only searching plugin cwd, missing files in parent directory)
- Fix health check session tracker to check stats file directly instead
  of depending on CLAUDE_PLUGIN_ROOT env var
- Fix session-end report to print in SessionEnd hook (Stop hook output
  doesn't render on /exit)
- Update v2 API endpoint to v3 in git commit capture search
- Keep auto_import.py as only direct REST write path (project profiles,
  idempotent, hash-gated)

mem0-plugin/scripts/on_stop.sh

@@ -62,14 +62,6 @@ If nothing notable happened in this interaction, it's fine to skip. Only store g
 Always include `app_id` (the active project_id from SessionStart) as a top-level parameter in every `add_memory` call.
 EOF
 
-# Capture transcript state in the background via Mem0 REST API
 SESSION_ID=$(echo "$INPUT" | jq -r '.session_id // ""' 2>/dev/null || echo "")
-echo "$INPUT" | python3 "$SCRIPT_DIR/on_pre_compact.py" --source=session-end 2>/dev/null &
-
-# Mark session as captured so SessionEnd hook can skip duplicate capture
-if [ -n "$SESSION_ID" ]; then
-  mkdir -p "$HOME/.mem0" 2>/dev/null || true
-  touch "$HOME/.mem0/.captured_${SESSION_ID}" 2>/dev/null || true
-fi
 
 exit 0