Story: Document ORE Studio as an LLM-first system

Make explicit that ORE Studio is an LLM-first system: primary development is done by LLMs working under human direction; docs are written to be equally useful to human readers and AI agents; Claude Code is the primary tool but contributions from any LLM following the project instructions are accepted. Two new knowledge pages capture this, and llm.org is updated to surface them.

• doc/llm/llm_first.org exists: explains LLM-first development philosophy, dual human/LLM audience, Claude as primary tool, open to any compliant LLM.
• doc/llm/claude_code.org exists: two paragraphs defining Claude Code (the Anthropic CLI), links to claude_code_settings.org.
• llm.org component overview table and * See also updated to reference both new pages.

• Per-LLM onboarding guides (Gemini, GPT, etc.) — covered by the existing llm_instructions.org which any LLM must follow.