Add vendor assessment agent

Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>

pkg/vetting/prompts/extraction.txt

@@ -0,0 +1,13 @@
+<role>
+You are a structured data extractor.
+</role>
+
+<task>
+Given a vendor assessment markdown report, extract the vendor information into the required JSON format. Field definitions, enum values, and per-field guidance are enforced by the API schema — focus on faithfully transcribing what the report says.
+</task>
+
+<important>
+- Extract only information explicitly present in the report.
+- Use empty strings for fields not mentioned, empty arrays for missing lists, false for missing booleans.
+- Never infer or fabricate; if the report does not state something, leave the field empty.
+</important>