fix: improve release visibility and cache handling

app.py

@@ -75,23 +75,32 @@ BUILD_INFO = load_build_info()
 
 
 def load_whats_new_summary():
-    """Load compact release notes for the What's New dialog."""
+    """Load compact release-note metadata for the What's New dialog."""
     try:
         with open(WHATS_NEW_SUMMARY_FILE, "r", encoding="utf-8") as f:
             data = json.load(f)
     except Exception as e:
         print(f"[What's New Error] {e}")
-        return []
+        return {"version": "unknown", "items": []}
 
-    items = data.get("items") if isinstance(data, dict) else None
+    if not isinstance(data, dict):
+        return {"version": "unknown", "items": []}
+
+    version = data.get("version")
+    items = data.get("items")
     if not isinstance(items, list):
-        return []
+        items = []
 
-    return [
-        item.strip()
-        for item in items
-        if isinstance(item, str) and item.strip()
-    ][:5]
+    return {
+        "version": version.strip()
+        if isinstance(version, str) and version.strip()
+        else "unknown",
+        "items": [
+            item.strip()
+            for item in items
+            if isinstance(item, str) and item.strip()
+        ][:5]
+    }
 
 
 WHATS_NEW_SUMMARY = load_whats_new_summary()
@@ -101,9 +110,36 @@ def inject_build_info():
     """Make build metadata and release-note summary available in templates."""
     return {
         "build_info": BUILD_INFO,
-        "whats_new_summary": WHATS_NEW_SUMMARY
+        "whats_new_summary": WHATS_NEW_SUMMARY,
+        "static_asset_url": static_asset_url
     }
 
+
+def get_static_asset_version(build_info=None):
+    """Return the preferred cache-busting build identifier."""
+    info = build_info or BUILD_INFO
+    for key in ("commit", "version"):
+        value = info.get(key) if isinstance(info, dict) else None
+        if isinstance(value, str) and value.strip() and value.strip() != "unknown":
+            return value.strip()
+    return None
+
+
+def static_asset_url(filename):
+    """Build a URL for RollCalc-owned static assets with a build query."""
+    asset_version = get_static_asset_version()
+    if asset_version:
+        return url_for("serve_static", filename=filename, v=asset_version)
+    return url_for("serve_static", filename=filename)
+
+
+@app.after_request
+def add_html_cache_policy(response):
+    """Require revalidation for dynamic HTML while leaving static caching intact."""
+    if response.mimetype == "text/html":
+        response.headers["Cache-Control"] = "no-cache"
+    return response
+
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