Add Scene 7 claim report workflow

docs/exhibit-data-model.md

@@ -128,7 +128,8 @@ CREATE TABLE osint.document_exhibits (
   title TEXT NOT NULL,
   published_at TIMESTAMPTZ,
   captured_at TIMESTAMPTZ,
-  source_uri TEXT
+  source_uri TEXT,
+  citation_text TEXT NOT NULL DEFAULT ''
 );
 
 CREATE TABLE osint.image_documents (
@@ -154,6 +155,24 @@ CREATE TABLE osint.event_exhibits (
 
 The service validates that every base exhibit has exactly one subtype row matching `exhibit_type_id`.
 
+### Claim and report semantics
+
+A Claim is a pinned proposition the investigator is asked to establish, such as
+**“Nils Aall Barricelli was an inventor.”** It is an Exhibit subtype rather than
+text hidden in a widget or a connection. One Claim can therefore receive multiple
+supporting red threads without becoming a knowledge-graph hub.
+
+For a Claim-to-Document connection, the connection label is the evidentiary
+statement—initially `Proof that…`—and the Document supplies the source date,
+human-readable `citation_text`, and optional `source_uri`. Stable board-local
+numbers live in `exhibit_citations`; they do not depend on z-order or position.
+
+`case_reports` holds clonable board configuration. Mutable, server-evaluated
+filings live in `case_report_submissions`, with individual deficiencies in
+`case_report_submission_issues`. A report can therefore record the useful state
+“evidence accepted, report incomplete” without weakening the evidence match or
+pretending the level has been fully accepted.
+
 ### Event semantics
 
 An event is an investigator-authored assertion: **“this happened.”** It is not source evidence and must not silently inherit a document's publication time.