Update docs to Plano (#639)

docs/source/resources/db_setup/conversation_states.sql

@@ -0,0 +1,31 @@
+-- Conversation State Storage Table
+-- This table stores conversational context for the OpenAI Responses API
+-- Run this SQL against your PostgreSQL/Supabase database before enabling conversation state storage
+
+CREATE TABLE IF NOT EXISTS conversation_states (
+    response_id TEXT PRIMARY KEY,
+    input_items JSONB NOT NULL,
+    created_at BIGINT NOT NULL,
+    model TEXT NOT NULL,
+    provider TEXT NOT NULL,
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Indexes for common query patterns
+CREATE INDEX IF NOT EXISTS idx_conversation_states_created_at
+    ON conversation_states(created_at);
+
+CREATE INDEX IF NOT EXISTS idx_conversation_states_provider
+    ON conversation_states(provider);
+
+-- Optional: Add a policy for automatic cleanup of old conversations
+-- Uncomment and adjust the retention period as needed
+-- CREATE INDEX IF NOT EXISTS idx_conversation_states_updated_at
+--     ON conversation_states(updated_at);
+
+COMMENT ON TABLE conversation_states IS 'Stores conversation history for OpenAI Responses API continuity';
+COMMENT ON COLUMN conversation_states.response_id IS 'Unique identifier for the conversation state';
+COMMENT ON COLUMN conversation_states.input_items IS 'JSONB array of conversation messages and context';
+COMMENT ON COLUMN conversation_states.created_at IS 'Unix timestamp (seconds) when the conversation started';
+COMMENT ON COLUMN conversation_states.model IS 'Model name used for this conversation';
+COMMENT ON COLUMN conversation_states.provider IS 'LLM provider (e.g., openai, anthropic, bedrock)';