Reorganize /docs with numbered TOC; deployment rewrite for actual homelab

- /docs/ now contains 12 numbered guides + index.md (navigator).
- Old duplicates removed: nexa-core/doc/, DEPLOYMENT.md, PLAN.md,
  config/{classification_logic,workflows_spec}.md.
- 09-deployment.md targets the running infra (LXC 104 docker host,
  Zoraxy at 192.168.1.4, existing Memos/n8n/LiteLLM/Nextcloud/Qdrant)
  rather than spinning a parallel stack; minimal-config approach.
- 11-open-questions.md tracks user-info-required blockers.
- 12-optimization-opportunities.md captures homelab tweaks.
- CLAUDE.md added so future agent runs know repo conventions and infra.

README.md

@@ -1 +1,17 @@
-# nexa
+# nexa
+
+**Neural Nexus for Information & Automation** — central nervous system for a personal IT setup.
+
+> Memos = voice & ear · n8n = reflexes · SAIA (LiteLLM) = brain · Qdrant (+ optional graph DB) = memory · Nextcloud = hands.
+
+## Start here
+
+📖 **[docs/index.md](./docs/index.md)** — TOC, reading paths, repo layout.
+
+## Repository layout
+
+```
+nexa/
+├── docs/        ← all documentation, numbered for reading order
+└── nexa-core/   ← runtime: n8n workflows, configs, prompts, scripts
+```