Fix entity extraction prompt to prevent literal 'type:' output
The LLM was interpreting "* type: name - description" literally,
outputting "* type: Person - Name - ..." which broke parsing.
Changed to explicit format with examples:
* Type: Entity Name - Description
Example:
* Person: Alice Smith - Mentioned in Slack...
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>