feat(mem0-agent): read path, hooks, maintenance, CLI and skills

- pack.py: single-call context pack, budgeted, sanitized, cached, with
  served-id tracking that turns a citation into POSITIVE feedback
- assist.py: error-signature lookup (never raw stdout, which returned 0 results in v1)
- maintain.py: transactional consolidation (add merged -> verify -> delete sources)
- transcript.py: JSONL parsing into non-overlapping windows via a cursor
- cli.py: the twelve commands the hooks invoke; detached assist queues a block
  that the next prompt hook drains, keeping the hot path network-free
- hooks generated from one spec; plugin manifest, MCP wiring, five skills

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

integrations/mem0-agent/.claude-plugin/plugin.json

@@ -0,0 +1,21 @@
+{
+  "name": "mem0-agent",
+  "version": "0.1.0",
+  "description": "Coding-agent memory that remembers your preferences, decisions and hard-won gotchas across sessions, machines and editors",
+  "author": {
+    "name": "Mem0",
+    "url": "https://mem0.ai"
+  },
+  "homepage": "https://docs.mem0.ai",
+  "repository": "https://github.com/mem0ai/mem0",
+  "license": "Apache-2.0",
+  "keywords": ["memory", "mem0", "context", "personalization"],
+  "userConfig": {
+    "api_key": {
+      "type": "string",
+      "description": "Mem0 API key from https://app.mem0.ai. Stored in your OS keychain, never written to a file.",
+      "sensitive": true,
+      "required": true
+    }
+  }
+}