feat: add web_search_tool config option to cortex_agent materialization

[Matts52]

Summary

Closes #11.

Adds a web_search_tool boolean config key (default false) to the cortex_agent materialization. When enabled, the generated DDL includes a TOOLS clause with the WEB_SEARCH_TOOL entry — no resource binding required.

Usage:

{{ config(
    materialized    = 'cortex_agent',
    web_search_tool = true
) }}

Compiles to:

create or replace agent MY_DB.MY_SCHEMA.MY_AGENT
tools = (
  { TYPE = WEB_SEARCH_TOOL, NAME = 'web_search' }
)
from specification
$$
...
$$

Setting web_search_tool = false or omitting it produces no TOOLS clause.

Changes

• macros/relations/cortex_agent/create.sql — build a tools_list in spec mode; append the web search entry when enabled; render TOOLS = (...) only when the list is non-empty
• integration_tests/models/agent_with_web_search.sql — new integration test model exercising the new config
• integration_tests/macros/assert_agents_exist.sql — add agent_with_web_search to the expected agent list
• README.md — document web_search_tool in the config reference table and add a "Enabling web search" usage section

Test plan

• dbt compile on the new agent_with_web_search model and verify the compiled SQL contains the TOOLS = ( { TYPE = WEB_SEARCH_TOOL, NAME = 'web_search' } ) clause
• Verify existing models without web_search_tool produce no TOOLS clause
• Run dbt build --target snowflake in integration_tests/ and confirm all agents are created
• Run dbt run-operation assert_agents_exist --target snowflake and confirm agent_with_web_search passes

🤖 Generated with Claude Code