* docs: improve agent memory guide onboarding and usage guidance
* docs: align Agent Memory guide with persistence implementation
* docs: fix misleading index_path persistence claim across guides
VectorStore's index_path kwarg is silently absorbed into FAISSStore's
**config and never read anywhere in faiss_store.py, so it does not make
the FAISS index persist across restarts as several docs implied. Real
persistence requires an explicit VectorStore.save()/.load() call, or
AgentContext.save()/.load() which cascades to it.
- docs/reference/context.md: rewrite the "Persist your vector store"
tip to explain the actual save()/load() mechanism instead of the
dead index_path kwarg.
- docs/guides/graphrag.md, decision-intelligence.md, ingest.md,
semantic-extraction.md: drop the dead index_path=... kwarg from
VectorStore(backend="faiss", ...) constructor calls.
Follow-up to #691, which fixed the same false claim in
docs/guides/agent-memory.md but missed these other files.
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Co-authored-by: KaifAhmad1 <kaifahmad087@gmail.com>
Zohaib Hassnain