docs: bring the llms.txt and llms-full.txt headers in line with the CLI setup

[zantvoort]

Summary

Follow-up to #666: aligns the agent-facing summaries in llms.txt and the llms-full.txt header with what the CLI does and how it is set up.

• An existing rules file (such as CLAUDE.md) keeps its content; Storm adds its own marked block.
• The MCP server runs locally and is read-only: schema metadata only, never the database credentials, row data only when the user enables it.
• init and demo are marked as interactive commands for the user to run in a terminal (Node.js 18+), so an agent reading the file does not try to run them itself.
• Adds the global install (npm install -g @storm-orm/cli), the storm init / storm demo forms, and storm update as the non-interactive refresh.

Verification

• bash website/scripts/generate-llms-full.sh regenerates llms-full.txt with the new header.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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