fix: improve release visibility and cache handling

PROJECT_KNOWLEDGE.md

@@ -55,6 +55,21 @@ If `build_info.json` is missing, malformed, or does not contain a usable value,
 
 The data is loaded centrally in `app.py` and made available to every template as `build_info`.
 
+## Cache and Release Visibility
+
+RollCalc uses the current build identifier to cache-bust RollCalc-owned static assets referenced by active templates. The preferred identifier is `build_info.commit`; if it is missing or `unknown`, the fallback is `build_info.version`.
+
+Dynamic HTML responses are sent with `Cache-Control: no-cache` so the calculator and Help pages are revalidated after deployments. Static assets are not globally marked no-cache; versioned URLs are used for active static JSON assets instead.
+
+For releases, keep these sources aligned:
+
+- `build_info.json`
+- the default `VERSION` in `scripts/update_build_info.sh`, unless deployment overrides it
+- the newest heading in `docs/de/recent_changes.md`
+- `version` in `static/recent_changes.json`
+
+The Recent Changes page includes a persistent force-reload fallback note for users whose browser still shows an older interface after deployment.
+
 ## Help and User Manual
 
 The in-app Help area keeps `docs/de/user_manual.md` as the leading German documentation source. RollCalc reads the Markdown file on each `/help/user-manual` request and renders it server-side with `markdown-it-py`.
@@ -105,7 +120,7 @@ The short dialog item list is maintained separately in:
 static/recent_changes.json
 ```
 
-This JSON is a compact summary for the dialog, not the complete release history. Keep it aligned with the most relevant current entries from `docs/de/recent_changes.md`.
+This JSON is a compact summary for the dialog, not the complete release history. It contains a `version` field and an `items` list. The browser displays the dialog only when the JSON version matches `build_info.version`; mismatched or invalid JSON must not block the calculator.
 
 ## Authentication