diff --git a/src/generated_scene/generator.rs b/src/generated_scene/generator.rs
index 8eabb88..13ab5f5 100644
--- a/src/generated_scene/generator.rs
+++ b/src/generated_scene/generator.rs
@@ -291,6 +291,10 @@ const STATIC_PARAMS = {static_params_json};
 
 const COLUMN_DEFS = {column_defs_json};
 
+const COLUMNS = {columns_json};
+
+const REPORT_NAME = '{scene_id}';
+
 function normalizePayload(payload) {{
   if (typeof payload === 'string') {{
     try {{ return JSON.parse(payload); }} catch (_) {{ return {{}}; }}
@@ -404,44 +408,59 @@ const defaultDeps = {{
 }};
 
 async function buildBrowserEntrypointResult(args, deps = defaultDeps) {{
+  // 1. Parameter validation
   const validation = validateArgs(args);
   if (!validation.valid) {{
-    return {{
-      type: 'report-artifact',
-      report_name: '{scene_id}',
-      status: 'error',
-      error: 'Validation failed: ' + validation.errors.join(', '),
-      column_defs: COLUMN_DEFS,
-      columns: {columns_json},
+    return buildArtifact({{
+      status: 'blocked',
+      blockedReason: 'validation_failed',
+      reasons: validation.errors,
       rows: [],
-      counts: {{ detail_rows: 0 }},
-      partial_reasons: [],
-      reasons: validation.errors
-    }};
+      args
+    }});
   }}
-  
+
+  // 2. Page context validation
+  const pageValidation = typeof deps.validatePageContext === 'function'
+    ? deps.validatePageContext(args)
+    : {{ ok: true }};
+  if (!pageValidation?.ok) {{
+    return buildArtifact({{
+      status: 'blocked',
+      blockedReason: pageValidation?.reason || 'page_context_mismatch',
+      reasons: [pageValidation?.reason || 'page_context_mismatch'],
+      rows: [],
+      args
+    }});
+  }}
+
+  // 3. Data fetching
+  const reasons = [];
+  let rawData = null;
   try {{
-    const rawData = await (deps.queryData ? deps.queryData(args) : Promise.resolve([]));
-    const rows = normalizeRows(rawData);
-    return buildArtifact({{ args, rows }});
+    rawData = await (deps.queryData ? deps.queryData(args) : Promise.resolve([]));
   }} catch (error) {{
-    return {{
-      type: 'report-artifact',
-      report_name: '{scene_id}',
+    return buildArtifact({{
       status: 'error',
-      error: error.message,
-      column_defs: COLUMN_DEFS,
-      columns: {columns_json},
+      fatalError: error.message,
+      reasons: ['api_query_failed:' + error.message],
       rows: [],
-      counts: {{ detail_rows: 0 }},
-      partial_reasons: [],
-      reasons: [error.message]
-    }};
+      args
+    }});
   }}
+
+  // 4. Row normalization
+  const rows = normalizeRows(rawData);
+  if (rows.length === 0 && Array.isArray(rawData) && rawData.length > 0) {{
+    reasons.push('row_normalization_partial');
+  }}
+
+  // 5. Build artifact
+  return buildArtifact({{ reasons, rows, args }});
 }}
 
 if (typeof module !== 'undefined') {{
-  module.exports = {{ buildBrowserEntrypointResult, normalizePayload, validateArgs, buildRequest, normalizeRows, buildArtifact, API_ENDPOINTS, STATIC_PARAMS, COLUMN_DEFS }};
+  module.exports = {{ buildBrowserEntrypointResult, normalizePayload, validateArgs, buildRequest, normalizeRows, buildArtifact, determineArtifactStatus, API_ENDPOINTS, STATIC_PARAMS, COLUMN_DEFS, COLUMNS, REPORT_NAME }};
 }}
 
 if (typeof args !== 'undefined') {{