[karmendra8386]

Follow-up to #308 and #325. #325 swapped the deprecated http_request/shell imports for vended equivalents; these two samples were left out there because retrieve has no vended equivalent — the tools repo deprecation table prescribes MemoryManager + BedrockKnowledgeBaseStore(writable=False) instead. This PR makes that change.

Changes

multi-modal-email-assistant-agent/kb_rag.py

• retrieve_from_kb() now searches via a MemoryManager backed by a read-only BedrockKnowledgeBaseStore (same KB ID, region, min_score, and 5-result limit as before) and returns the same {status, content: [{text}]} shape its caller already consumes.
• The analyzer agent receives the memory manager instead of tools=[retrieve]; the env-var configuration the old tool needed is gone.

genai-powered-financial-advisor-tools/application/chat.py

• The meeting-analysis agent builds a read-only KB store for the per-query KB ID and passes a MemoryManager instead of tools=[retrieve].
• The manager's search tool keeps the name retrieve, so the existing system prompt ("Use the retrieve tool FIRST…") stays accurate with no prompt changes.

Both use injection=False, so retrieval stays agent-driven through the search tool, matching the old tool's behavior rather than adding automatic context injection.

Verification

• Both files compile; the store/manager construct against the current SDK (strands-agents 1.57).
• retrieve_from_kb's return contract exercised locally with a stubbed search (entries joined into content[0].text as the caller expects).
• Not run end-to-end against a live Bedrock Knowledge Base (no KB available in my environment) — the retrieval call itself is the SDK's maintained Retrieve path.

Out of scope

email_assistant.py in the same sample folder still imports the deprecated editor tool. Happy to include it here or as a separate change, whichever the maintainers prefer.