Add user-facing FableCodex workflow examples

[baskduf]

Description

Add user-facing workflow examples to make FableCodex easier to adopt. The project is now well-tested and released; examples would help users understand when and how to use the skill.

Suggested Examples

• Debugging workflow
• PR review workflow
• Long-running goal ledger workflow
• Findings gate failure and recovery
• Lightweight review without ledgers

Acceptance Criteria

• Add examples under examples/ or docs/examples/.
• Each example includes:
  • prompt text
  • expected workflow
  • command/evidence snippets where relevant
• Link the examples from README.md.
• Keep examples honest about FableCodex limitations; do not imply model capability changes.