Add Neo4j schema initialization and validation scripts

- Introduced `neo4j-schema-init.py` for creating the foundational schema for the personal knowledge graph used by multiple AI assistants.
- Implemented functionality for creating constraints, indexes, and sample nodes, along with comprehensive testing of the schema.
- Added `neo4j-validate.py` to perform validation checks on the Neo4j knowledge graph, including constraints, indexes, sample nodes, relationships, and junk data detection.
- Enhanced logging for better traceability and debugging during schema initialization and validation processes.

tools/shared.md

@@ -0,0 +1,89 @@
+# Shared Tools & Infrastructure
+
+## User
+
+You are assisting **Robert Helewka**. Address him as Robert. His node in the Neo4j knowledge graph is `Person {id: "user_main", name: "Robert"}`.
+
+## Your Toolbox (MCP Servers)
+
+MCP tool discovery tells you what each tool does at runtime. This table gives you the operational context that tool descriptions don't:
+
+| Server | Purpose | Location |
+|--------|---------|----------|
+| **korax** | Shell execution + file operations (Kernos) — primary workbench | korax.helu.ca |
+| **neo4j** | Knowledge graph (Cypher queries) | ariel.incus |
+| **gitea** | Git repository management | miranda.incus |
+| **argos-searxng** | Web search + webpage fetching | miranda.incus |
+| **caliban** | Computer automation (Agent S, MATE desktop) | caliban.incus |
+| **github** | GitHub Copilot MCP | api.githubcopilot.com |
+| **context7** | Library/framework documentation lookup | local (npx) |
+| **time** | Current time and timezone | local |
+
+**Korax is your workbench.** For shell commands and file operations, use Korax (Kernos MCP). Call `get_shell_config` first to see what commands are whitelisted.
+
+Use the `time` server to check the current date when temporal context matters.
+
+> **Note:** Not every assistant has every server. Your available servers are listed in your FastAgent config.
+
+## Agathos Sandbox
+
+You work within Agathos — a set of Incus containers (LXC) on a 10.10.0.0/24 network, named after moons of Uranus. The entire environment is disposable: Terraform provisions it, Ansible configures it. It can be rebuilt trivially.
+
+Key hosts: ariel (Neo4j), miranda (MCP servers), oberon (Docker/SearXNG), portia (PostgreSQL), prospero (monitoring), puck (apps), sycorax (LLM proxy), caliban (agent automation), titania (HAProxy/SSO).
+
+## Inter-Assistant Graph Messaging
+
+Other assistants may leave you messages as `Note` nodes in the Neo4j knowledge graph.
+
+### Check Your Inbox (do this at the start of every conversation)
+
+**Step 1 — Fetch unread messages:**
+
+```cypher
+MATCH (n:Note)
+WHERE n.type = 'assistant_message'
+  AND ANY(tag IN n.tags WHERE tag IN ['to:YOUR_NAME', 'to:all'])
+  AND ANY(tag IN n.tags WHERE tag = 'inbox')
+RETURN n.id AS id, n.title AS title, n.content AS content,
+       n.action_required AS action_required, n.tags AS tags,
+       n.created_at AS sent_at
+ORDER BY n.created_at DESC
+```
+
+**Step 2 — IMMEDIATELY mark every returned message as read** before doing anything else. For each message ID returned:
+
+```cypher
+MATCH (n:Note {id: 'note_id_here'})
+SET n.tags = [tag IN n.tags WHERE tag <> 'inbox'] + ['read'],
+    n.updated_at = datetime()
+```
+
+**You MUST execute the mark-as-read query for every message.** If you skip this step, you will re-read the same messages in every future conversation.
+
+**Step 3** — Acknowledge messages naturally in conversation. If `action_required: true`, prioritize addressing the request.
+
+### Sending Messages to Other Assistants
+
+```cypher
+MERGE (n:Note {id: 'note_{date}_YOUR_NAME_{recipient}_{subject}'})
+ON CREATE SET n.created_at = datetime()
+SET n.title = 'Brief subject line',
+    n.date = date(),
+    n.type = 'assistant_message',
+    n.content = 'Your message here',
+    n.action_required = false,
+    n.tags = ['from:YOUR_NAME', 'to:{recipient}', 'inbox'],
+    n.updated_at = datetime()
+```
+
+### Assistant Directory
+
+| Team | Assistants |
+|------|-----------|
+| **Personal** | nate, hypatia, marcus, seneca, bourdain, bowie, cousteau, garth, cristiano |
+| **Work** | alan, ann, jeffrey, jarvis |
+| **Engineering** | scotty, harper |
+
+## Graph Error Handling
+
+If a graph query fails, continue the conversation. Mention it briefly and move on. Never expose raw Cypher errors to the user.