feat: add full_text_search() to CoordinodeClient + LangChain adapter

[polaz]

DB gate: R550 + R555 (Phase 5.3 — Full-Text Search procedures, not yet implemented)

Task

• Add full_text_search(label, property, query) → list[NodeResult] to CoordinodeClient
• Add keyword_search() to LangChain adapter

[coderabbitai]

⚠️ Possible Duplicate Issue(s)

• feat: add full_text_search() to CoordinodeClient and LangChain keyword_search() #22

🔗 Related PRs

#27 - feat: similarity_search() for LangChain + upsert_relations() idempotency test [merged]

---

📝 Issue Planner

_{Check the box below or use the @coderabbitai plan command to generate an implementation plan and prompts that you can use with your favorite coding assistant.}

• Create Plan

---

🧪 Issue enrichment is currently in open beta.

You can configure auto-planning by selecting labels in the issue_enrichment configuration.

To disable automatic issue enrichment, add the following to your .coderabbit.yaml:

issue_enrichment:
  auto_enrich:
    enabled: false

💬 Have feedback or questions? Drop into our discord!