3 example projects (schema+codegen, RDF pipeline, LLM validation)

[simontaurus]

Create 3 example projects: (1) Schema design + code generation, (2) RDF data integration pipeline, (3) LLM structured output with OO-LD validation.

Acceptance Criteria

• Example 1: Schema design + code generation
• Example 2: RDF data integration pipeline
• Example 3: LLM structured output with OO-LD validation
• Each example is self-contained and runnable

[simontaurus]

Moved to OO-LD/oold-tutorial (issues #2, #3, #4)