fix(mem0-plugin): remove userConfig from plugin.json, add auto-deps install

- Remove userConfig from .claude-plugin/plugin.json — OAuth flow handles
  auth via mcp.mem0.ai, userConfig prompt was redundant and confusing
- Add ensure_deps.sh to install mem0ai SDK into persistent plugin venv
- Add requirements.txt (mem0ai) for dependency tracking
- Wire SessionStart hook to auto-install deps on first run
- Update setup_coding_categories.py to find venv site-packages
- Update onboarding SKILL.md with venv-aware install steps

mem0-plugin/scripts/ensure_deps.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+# Install mem0ai SDK into a persistent venv inside CLAUDE_PLUGIN_DATA.
+# Runs on SessionStart; skips if requirements.txt hasn't changed.
+set -euo pipefail
+
+PLUGIN_ROOT="${CLAUDE_PLUGIN_ROOT:-$(cd "$(dirname "$0")/.." && pwd)}"
+DATA_DIR="${CLAUDE_PLUGIN_DATA:-${HOME}/.mem0/plugin-data}"
+VENV_DIR="${DATA_DIR}/venv"
+REQ_SRC="${PLUGIN_ROOT}/requirements.txt"
+REQ_STAMP="${DATA_DIR}/requirements.txt"
+
+mkdir -p "${DATA_DIR}"
+
+needs_install=false
+
+if [ ! -f "${VENV_DIR}/bin/python3" ]; then
+  needs_install=true
+elif ! diff -q "${REQ_SRC}" "${REQ_STAMP}" >/dev/null 2>&1; then
+  needs_install=true
+fi
+
+if [ "${needs_install}" = "true" ]; then
+  python3 -m venv "${VENV_DIR}" 2>/dev/null || python -m venv "${VENV_DIR}"
+  "${VENV_DIR}/bin/pip" install --quiet --upgrade pip >/dev/null 2>&1 || true
+  if "${VENV_DIR}/bin/pip" install --quiet -r "${REQ_SRC}" 2>/dev/null; then
+    cp "${REQ_SRC}" "${REQ_STAMP}"
+  else
+    rm -f "${REQ_STAMP}"
+    echo "mem0 plugin: failed to install Python dependencies" >&2
+    exit 0
+  fi
+fi

mem0-plugin/scripts/setup_coding_categories.py

@@ -5,15 +5,14 @@ mem0 auto-tags every memory with one or more `categories`. By default the list
 is consumer-oriented (food, hobbies, music, ...), which is meaningless for code.
 This script replaces the project's category list with a coding-focused one.
 
-The change is project-level (per the platform docs, per-request overrides are
-not supported on the managed API). Run once per project; future memories will
-be tagged using the new list automatically.
+Uses the mem0ai SDK (client.project.update). The SDK is installed into a
+persistent venv at ${CLAUDE_PLUGIN_DATA}/venv by the ensure_deps.sh hook.
 
 Usage:
-  python setup_coding_categories.py            # dry-run: show current vs proposed, no changes
+  python setup_coding_categories.py            # dry-run: show current vs proposed
   python setup_coding_categories.py --apply    # actually call project.update()
 
-Requires the mem0ai Python SDK and MEM0_API_KEY (or CLAUDE_PLUGIN_OPTION_MEM0_API_KEY) to be set.
+Requires MEM0_API_KEY (or CLAUDE_PLUGIN_OPTION_MEM0_API_KEY).
 """
 
 from __future__ import annotations
@@ -23,8 +22,18 @@ import json
 import os
 import sys
 
-sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
-from _identity import resolve_api_key
+_script_dir = os.path.dirname(os.path.abspath(__file__))
+sys.path.insert(0, _script_dir)
+from _identity import resolve_api_key  # noqa: E402
+
+_plugin_root = os.environ.get("CLAUDE_PLUGIN_ROOT", os.path.join(_script_dir, ".."))
+_data_dir = os.environ.get("CLAUDE_PLUGIN_DATA", os.path.join(os.path.expanduser("~"), ".mem0", "plugin-data"))
+_venv_site = os.path.join(_data_dir, "venv", "lib")
+if os.path.isdir(_venv_site):
+    for d in sorted(os.listdir(_venv_site)):
+        sp = os.path.join(_venv_site, d, "site-packages")
+        if os.path.isdir(sp) and sp not in sys.path:
+            sys.path.insert(1, sp)
 
 CODING_CATEGORIES = [
     {
@@ -160,9 +169,9 @@ def main() -> int:
         from mem0 import MemoryClient
     except ImportError:
         print(
-            "ERROR: the mem0ai Python SDK is not installed.\n"
-            "Install with: pip install mem0ai\n"
-            "Then re-run this script.",
+            "ERROR: mem0ai SDK not found. The plugin's ensure_deps.sh hook should\n"
+            "install it automatically on session start. Try restarting Claude Code,\n"
+            "or run manually:  pip install mem0ai",
             file=sys.stderr,
         )
         return 1