Merged in feature/chatbot1 (pull request #223)

Chatbot functionality

* baseline working

* missing test file

* more tests

internal/database/queries/custommetadata.sql

@@ -120,6 +120,39 @@ SELECT custom_schema_id
 FROM documents
 WHERE id = @id;
 
+-- name: GetDocumentCustomSchemaIdForClient :one
+-- Chatbot-scoped variant of GetDocumentCustomSchemaId: adds a clientId
+-- filter so cross-client lookups miss with pgx.ErrNoRows. Same scalar
+-- result type (nullable uuid) as the non-scoped query — only the WHERE
+-- clause differs. Plan §5.
+SELECT custom_schema_id
+FROM documents
+WHERE id = @id
+  AND clientId = @client_id;
+
+-- name: GetCurrentDocumentCustomMetadataForClient :one
+-- Chatbot-scoped variant of GetCurrentDocumentCustomMetadata. Same column
+-- set (the metadata row decorated with schema id/name/version), but the
+-- joined documents row must belong to @client_id; cross-client calls miss
+-- with pgx.ErrNoRows. Plan §5.
+SELECT
+    dcm.id,
+    dcm.document_id,
+    dcm.metadata,
+    dcm.version,
+    dcm.created_at,
+    dcm.created_by,
+    cms.id          AS schema_id,
+    cms.name        AS schema_name,
+    cms.version     AS schema_version
+FROM document_custom_metadata dcm
+JOIN documents d ON d.id = dcm.document_id
+LEFT JOIN client_metadata_schemas cms ON cms.id = d.custom_schema_id
+WHERE dcm.document_id = @document_id
+  AND d.clientId      = @client_id
+ORDER BY dcm.version DESC
+LIMIT 1;
+
 -- name: GetDocumentClientID :one
 -- Read a document's clientId for the AssignSchema cross-client check.
 -- documents.clientId is the unquoted (lowercased) varchar column.