Add Claude Code plugin scaffold for single-repo install

Consolidates plugin components (hooks, commands, skills, MCP config)
into this repo so it can be installed with:
  claude plugins install github:ViktorBarzin/claude-memory-mcp

- .claude-plugin/plugin.json: manifest with all hook events
- mcp/memory-mcp.json: MCP server config using existing src/
- hooks/: compaction survival, auto-recall, auto-learn, auto-approve
- commands/: /remember and /recall slash commands
- skills/: memory-management skill
- Bump MCP server to v2.0.0 with metaclaw migration fallback
- Update README with quick install and plugin hooks docs

hooks/post-compact-recovery.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+# UserPromptSubmit hook: Inject recovery context after compaction
+# This hook runs on each user prompt, but only injects context once after compaction.
+
+# Read hook input from stdin
+INPUT=$(cat)
+
+# Extract session ID
+SESSION_ID=$(echo "$INPUT" | jq -r '.session_id // .sessionId // "unknown"')
+
+# Define marker path
+MEMORY_HOME="${MEMORY_HOME:-$HOME/.claude/claude-memory}"
+MARKER_DIR="${MEMORY_HOME}/state/compaction-markers"
+MARKER_FILE="${MARKER_DIR}/${SESSION_ID}.json"
+
+# Fast path: no marker means no recent compaction, exit immediately
+if [ ! -f "$MARKER_FILE" ]; then
+    exit 0
+fi
+
+# Read marker contents
+MARKER=$(cat "$MARKER_FILE")
+
+# Validate JSON before processing
+if ! echo "$MARKER" | jq -e . >/dev/null 2>&1; then
+    rm -f "$MARKER_FILE"
+    exit 0
+fi
+
+# Extract data from marker
+COMPACTED_AT=$(echo "$MARKER" | jq -r '.compactedAt // "unknown"')
+PERSONALITY=$(echo "$MARKER" | jq -r '.personalityReminder // ""')
+
+# Build remembered facts summary (limit to ~500 chars)
+FACTS_SUMMARY=$(echo "$MARKER" | jq -r '
+    .rememberedFacts[:10] |
+    map("- [\(.category // "fact")] \(.content)") |
+    join("\n")
+' 2>/dev/null || echo "")
+
+# Build recovery context (kept under 1000 tokens)
+RECOVERY_CONTEXT="[Claude Memory Recovery - Context compacted at ${COMPACTED_AT}]
+
+${PERSONALITY}
+
+Key memories from before compaction:
+${FACTS_SUMMARY}
+
+Use the memory_recall MCP tool if you need more context about past conversations."
+
+# Output JSON with additional context for injection
+cat << EOF
+{
+  "hookSpecificOutput": {
+    "hookEventName": "UserPromptSubmit",
+    "additionalContext": $(echo "$RECOVERY_CONTEXT" | jq -Rs .)
+  }
+}
+EOF
+
+# Delete marker file (one-time injection)
+rm -f "$MARKER_FILE"
+
+exit 0