feat: add in-app release notes and what's new dialog

PROJECT_KNOWLEDGE.md

@@ -18,6 +18,7 @@ Backend:
 - `/` renders the active calculator template.
 - `/help` renders the authenticated Help landing page.
 - `/help/user-manual` renders `docs/de/user_manual.md` server-side inside the RollCalc Help layout.
+- `/help/recent-changes` renders `docs/de/recent_changes.md` server-side inside the RollCalc Help layout.
 - `/help/user-manual/screenshots/<path:filename>` serves German manual screenshots from `docs/de/screenshots/`.
 - `/static/<path:filename>` is intended to serve static files behind Basic Auth.
 - `/api/health` returns health/version information.
@@ -77,6 +78,30 @@ Rendering rules:
 
 The Help pages use the same HTTP Basic Auth protection as the calculator.
 
+### Recent Changes and What's New
+
+Full user-facing release notes are maintained in:
+
+```text
+docs/de/recent_changes.md
+```
+
+The calculator header links directly to `/help/user-manual`. The Help landing page lists only existing documents, currently User Manual and Recent Changes.
+
+The startup What's New dialog uses `build_info.version` and is suppressed when the version is empty or `unknown`. The last acknowledged version is stored only in browser `localStorage` under:
+
+```text
+rollcalc_last_seen_version
+```
+
+The short dialog item list is maintained separately in:
+
+```text
+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`.
+
 ## Authentication
 
 RollCalc uses HTTP Basic Auth. User entries in `BETA_USERS` have this shape:

README.md

@@ -94,6 +94,7 @@ Implemented routes:
 | `/` | `GET` | Basic Auth | Renders `templates/roll_calculator.html`. |
 | `/help` | `GET` | Basic Auth | Renders the Help landing page. |
 | `/help/user-manual` | `GET` | Basic Auth | Reads `docs/de/user_manual.md`, renders it as HTML, and displays it in the RollCalc Help layout. |
+| `/help/recent-changes` | `GET` | Basic Auth | Reads `docs/de/recent_changes.md`, renders it as HTML, and displays it in the RollCalc Help layout. |
 | `/help/user-manual/screenshots/<path:filename>` | `GET` | Basic Auth | Serves German user-manual screenshots from `docs/de/screenshots/` only. |
 | `/static/<path:filename>` | `GET` | Basic Auth | Intended protected static-file serving from `static/`. |
 | `/api/health` | `GET` | Basic Auth | Returns app health and version. |
@@ -132,8 +133,16 @@ The user manual is available at:
 /help/user-manual
 ```
 
+Recent changes are available at:
+
+```text
+/help/recent-changes
+```
+
 `docs/de/user_manual.md` is the leading source for the German user manual. The app reads this Markdown file on request and renders it server-side with `markdown-it-py`; no generated static HTML copy is maintained. Raw HTML in the Markdown source is disabled during rendering.
 
+`docs/de/recent_changes.md` is the leading source for full German release notes. It is rendered through the same authenticated Markdown infrastructure.
+
 The documentation directory is prepared for additional languages:
 
 ```text
@@ -153,6 +162,24 @@ docs/de/screenshots/
 
 The application rewrites those relative Markdown image paths to the authenticated manual screenshot route, which is limited to the active language's screenshot directory.
 
+### What's New Dialog
+
+The calculator page shows a compact What's New dialog once per build version. The current version comes from `build_info.version`; if that value is empty or `unknown`, the dialog is not shown.
+
+The last acknowledged version is stored only in the browser:
+
+```text
+rollcalc_last_seen_version
+```
+
+The short dialog summary is maintained in:
+
+```text
+static/recent_changes.json
+```
+
+Keep `docs/de/recent_changes.md` as the complete release-note source and `static/recent_changes.json` as the short 3-5 item summary for the startup dialog.
+
 ## Frontend Entry Point
 
 The active UI is `templates/roll_calculator.html`.

app.py

@@ -22,6 +22,7 @@ import os
 from datetime import datetime
 import json
 import re
+import socket
 import unicodedata
 
 app = Flask(__name__)
@@ -59,6 +60,8 @@ BUILD_INFO_FILE = "build_info.json"
 DOCS_DIR = os.path.join(app.root_path, "docs")
 DEFAULT_DOC_LANGUAGE = "de"
 USER_MANUAL_FILENAME = "user_manual.md"
+RECENT_CHANGES_FILENAME = "recent_changes.md"
+WHATS_NEW_SUMMARY_FILE = os.path.join(app.root_path, "static", "recent_changes.json")
 UNKNOWN_BUILD_INFO = {
     "version": "unknown",
     "branch": "unknown",
@@ -91,10 +94,36 @@ def load_build_info():
 
 BUILD_INFO = load_build_info()
 
+
+def load_whats_new_summary():
+    """Load compact release notes 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 []
+
+    items = data.get("items") if isinstance(data, dict) else None
+    if not isinstance(items, list):
+        return []
+
+    return [
+        item.strip()
+        for item in items
+        if isinstance(item, str) and item.strip()
+    ][:5]
+
+
+WHATS_NEW_SUMMARY = load_whats_new_summary()
+
 @app.context_processor
 def inject_build_info():
-    """Make build metadata available in all templates."""
-    return {"build_info": BUILD_INFO}
+    """Make build metadata and release-note summary available in templates."""
+    return {
+        "build_info": BUILD_INFO,
+        "whats_new_summary": WHATS_NEW_SUMMARY
+    }
 
 # ============================================================================
 # AUTHENTICATION
@@ -132,6 +161,23 @@ def log_access(username, endpoint, method, status=200):
     except Exception as e:
         print(f"[Logging Error] {e}")
 
+
+def find_free_port(start_port=5000, max_attempts=10, host="0.0.0.0"):
+    """Find the first available TCP port at or above start_port."""
+    for port in range(start_port, start_port + max_attempts):
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
+            sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+            try:
+                sock.bind((host, port))
+            except OSError:
+                continue
+            return port
+
+    raise RuntimeError(
+        f"No free port found from {start_port} to "
+        f"{start_port + max_attempts - 1}"
+    )
+
 # ============================================================================
 # ROUTES
 # ============================================================================
@@ -151,9 +197,14 @@ def build_manual_renderer():
     return renderer
 
 
+def get_document_path(filename, language=DEFAULT_DOC_LANGUAGE):
+    """Return the Markdown path for a language-specific help document."""
+    return os.path.join(DOCS_DIR, language, filename)
+
+
 def get_manual_path(language=DEFAULT_DOC_LANGUAGE):
     """Return the Markdown path for a language-specific manual."""
-    return os.path.join(DOCS_DIR, language, USER_MANUAL_FILENAME)
+    return get_document_path(USER_MANUAL_FILENAME, language)
 
 
 def get_manual_screenshot_dir(language=DEFAULT_DOC_LANGUAGE):
@@ -199,13 +250,13 @@ def add_heading_ids_and_toc(tokens):
     return toc
 
 
-def render_user_manual(language=DEFAULT_DOC_LANGUAGE):
-    """Read and render the Markdown user manual into HTML and a generated TOC."""
+def render_markdown_document(filename, language=DEFAULT_DOC_LANGUAGE):
+    """Read and render a Markdown help document into HTML and a generated TOC."""
     renderer = build_manual_renderer()
-    manual_path = get_manual_path(language)
+    document_path = get_document_path(filename, language)
 
-    with open(manual_path, "r", encoding="utf-8") as manual_file:
-        markdown_text = manual_file.read()
+    with open(document_path, "r", encoding="utf-8") as document_file:
+        markdown_text = document_file.read()
 
     markdown_text = rewrite_manual_asset_paths(markdown_text, language)
     tokens = renderer.parse(markdown_text)
@@ -213,6 +264,16 @@ def render_user_manual(language=DEFAULT_DOC_LANGUAGE):
     html = renderer.renderer.render(tokens, renderer.options, {})
     return Markup(html), toc
 
+
+def render_user_manual(language=DEFAULT_DOC_LANGUAGE):
+    """Read and render the Markdown user manual."""
+    return render_markdown_document(USER_MANUAL_FILENAME, language)
+
+
+def render_recent_changes(language=DEFAULT_DOC_LANGUAGE):
+    """Read and render the Markdown recent changes document."""
+    return render_markdown_document(RECENT_CHANGES_FILENAME, language)
+
 @app.route("/", methods=["GET"])
 @auth.login_required
 def index():
@@ -236,6 +297,9 @@ def user_manual():
         manual_html, toc = render_user_manual(DEFAULT_DOC_LANGUAGE)
         return render_template(
             "user_manual.html",
+            document_title="User Manual",
+            document_subtitle="RollCalc technical user documentation",
+            error_title="User Manual unavailable",
             manual_html=manual_html,
             toc=toc,
             render_error=None
@@ -244,6 +308,9 @@ def user_manual():
         app.logger.exception("Could not render user manual")
         return render_template(
             "user_manual.html",
+            document_title="User Manual",
+            document_subtitle="RollCalc technical user documentation",
+            error_title="User Manual unavailable",
             manual_html=None,
             toc=[],
             render_error=(
@@ -252,6 +319,39 @@ def user_manual():
             )
         ), 500
 
+
+@app.route("/help/recent-changes", methods=["GET"])
+@auth.login_required
+def recent_changes():
+    """Render recent changes inside the RollCalc Help layout."""
+    log_access(auth.current_user(), "/help/recent-changes", "GET")
+    try:
+        changes_html, toc = render_recent_changes(DEFAULT_DOC_LANGUAGE)
+        return render_template(
+            "user_manual.html",
+            document_title="Recent Changes",
+            document_subtitle="RollCalc release notes",
+            error_title="Recent Changes unavailable",
+            manual_html=changes_html,
+            toc=toc,
+            render_error=None
+        )
+    except Exception:
+        app.logger.exception("Could not render recent changes")
+        return render_template(
+            "user_manual.html",
+            document_title="Recent Changes",
+            document_subtitle="RollCalc release notes",
+            error_title="Recent Changes unavailable",
+            manual_html=None,
+            toc=[],
+            render_error=(
+                "Recent changes could not be loaded. "
+                "Please contact the RollCalc maintainer if the problem persists."
+            )
+        ), 500
+
+
 @app.route("/help/user-manual/screenshots/<path:filename>", methods=["GET"])
 @auth.login_required
 def manual_screenshot(filename, language=DEFAULT_DOC_LANGUAGE):
@@ -317,21 +417,22 @@ def internal_error(e):
 if __name__ == "__main__":
     os.makedirs("templates", exist_ok=True)
     os.makedirs("static", exist_ok=True)
+    port = find_free_port(start_port=5000, max_attempts=10, host="0.0.0.0")
     
-    print("""
+    print(f"""
     ╔═══════════════════════════════════════════════════════════╗
     ║  Naue Roll Calculator - V14 + QoL Update                 ║
     ║  HTTP Basic Auth Enabled                                 ║
     ║                                                           ║
     ║  ⚠️  BEFORE PRODUCTION: Update passwords in app.py       ║
     ║                                                           ║
-    ║  Starten auf: http://localhost:5000                     ║
+    ║  Starten auf: http://localhost:{port:<5}                    ║
     ╚═══════════════════════════════════════════════════════════╝
     """)
     
     app.run(
         host="0.0.0.0",
-        port=5000,
+        port=port,
         debug=False,
         use_reloader=False
     )

docs/de/recent_changes.md

@@ -0,0 +1,9 @@
+# Recent Changes
+
+## Version 0.4
+
+- User Manual integrated into RollCalc.
+- Help area added for internal documentation.
+- Capacity Analysis presentation improved.
+- Governing Constraint highlighted more clearly.
+- Remaining Capacity added to the Capacity Summary.

static/recent_changes.json

@@ -0,0 +1,8 @@
+{
+  "items": [
+    "User Manual integrated",
+    "Capacity Analysis improved",
+    "Governing Constraint clarified",
+    "Remaining Capacity added"
+  ]
+}

templates/help_index.html

@@ -57,6 +57,13 @@
         </p>
         <a href="{{ url_for('user_manual') }}">Open User Manual</a>
       </article>
+      <article class="help-card">
+        <h2>Recent Changes</h2>
+        <p>
+          Compact release notes for relevant user-facing changes in RollCalc.
+        </p>
+        <a href="{{ url_for('recent_changes') }}">Open Recent Changes</a>
+      </article>
     </section>
   </main>
 

templates/roll_calculator.html

@@ -146,6 +146,59 @@
       background: #b8c7bf;
       cursor: not-allowed;
     }
+    .whats-new-overlay {
+      position: fixed;
+      inset: 0;
+      z-index: 9000;
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      padding: 20px;
+      background: rgba(20, 28, 34, 0.55);
+    }
+    .whats-new-overlay.is-hidden { display: none; }
+    .whats-new-dialog {
+      width: min(520px, 100%);
+      background: #fff;
+      border-radius: 8px;
+      box-shadow: 0 18px 42px rgba(0, 0, 0, 0.24);
+      overflow: hidden;
+    }
+    .whats-new-header {
+      padding: 16px 20px;
+      background: #1F5438;
+      color: #fff;
+    }
+    .whats-new-header h2 { font-size: 18px; margin: 0 0 4px; }
+    .whats-new-version { font-size: 12px; opacity: 0.88; }
+    .whats-new-content {
+      padding: 18px 20px 8px;
+      font-size: 14px;
+      line-height: 1.5;
+      color: #333;
+    }
+    .whats-new-content ul { margin: 8px 0 0 20px; }
+    .whats-new-content li { margin-bottom: 5px; }
+    .whats-new-actions {
+      display: flex;
+      justify-content: flex-end;
+      gap: 10px;
+      padding: 16px 20px 18px;
+      border-top: 1px solid #e0e8f0;
+      background: #f8fafa;
+    }
+    .whats-new-btn {
+      border: none;
+      border-radius: 6px;
+      padding: 9px 14px;
+      font-size: 13px;
+      font-weight: 700;
+      cursor: pointer;
+    }
+    .whats-new-btn-primary { background: #2BAC70; color: #fff; }
+    .whats-new-btn-primary:hover { background: #1F5438; }
+    .whats-new-btn-secondary { background: #fff; color: #1F5438; border: 1px solid #a8c8ba; }
+    .whats-new-btn-secondary:hover { background: #eef4f1; }
 
     /* ============================================
        LOAD OPTIMIZER STYLES
@@ -453,6 +506,8 @@
     @media (max-width: 768px) {
       .header { padding: 18px 16px; }
       .header-inner { align-items: flex-start; }
+      .whats-new-actions { flex-direction: column; }
+      .whats-new-btn { width: 100%; }
       .lo-accordion-header h3 { font-size: 14px; }
       .lo-preset-buttons { flex-direction: column; }
       .lo-preset-btn { width: 100%; }
@@ -496,13 +551,29 @@
   </div>
 </div>
 
+<div class="whats-new-overlay is-hidden" id="whatsNewOverlay" role="dialog" aria-modal="true" aria-labelledby="whatsNewTitle">
+  <div class="whats-new-dialog">
+    <div class="whats-new-header">
+      <h2 id="whatsNewTitle">What’s New</h2>
+      <div class="whats-new-version">Version: <span id="whatsNewVersion">–</span></div>
+    </div>
+    <div class="whats-new-content">
+      <ul id="whatsNewList"></ul>
+    </div>
+    <div class="whats-new-actions">
+      <button class="whats-new-btn whats-new-btn-secondary" id="whatsNewOpenChangesBtn" type="button">Open Recent Changes</button>
+      <button class="whats-new-btn whats-new-btn-primary" id="whatsNewContinueBtn" type="button">Continue</button>
+    </div>
+  </div>
+</div>
+
 <div class="header">
   <div class="header-inner">
     <div>
       <h1>Naue Roll Diameter Calculator</h1>
       <p>Roll Diameter • Product Length • Roll Weight • Load Optimizer</p>
     </div>
-    <a class="header-help-link" href="{{ url_for('help_index') }}">Help</a>
+    <a class="header-help-link" href="{{ url_for('user_manual') }}">User Manual</a>
   </div>
 </div>
 
@@ -1573,12 +1644,81 @@ document.addEventListener('DOMContentLoaded', () => {
   window.loadOptimizerUI = new LoadOptimizerUI();
 });
 
+const ROLLCALC_BUILD_VERSION = {{ build_info.version|tojson }};
+const ROLLCALC_WHATS_NEW_ITEMS = {{ whats_new_summary|tojson }};
+const ROLLCALC_LAST_SEEN_VERSION_KEY = 'rollcalc_last_seen_version';
+
+function shouldShowWhatsNew(currentVersion, storedVersion) {
+  return !!currentVersion &&
+    currentVersion !== 'unknown' &&
+    currentVersion !== storedVersion;
+}
+
+function markWhatsNewSeen(currentVersion) {
+  if (!currentVersion || currentVersion === 'unknown') return;
+  try {
+    localStorage.setItem(ROLLCALC_LAST_SEEN_VERSION_KEY, currentVersion);
+  } catch (e) {
+    console.warn('Could not store RollCalc release note state', e);
+  }
+}
+
+function renderWhatsNewItems(items) {
+  const list = document.getElementById('whatsNewList');
+  if (!list) return;
+
+  list.innerHTML = '';
+  items.forEach(item => {
+    const li = document.createElement('li');
+    li.textContent = item;
+    list.appendChild(li);
+  });
+}
+
+function maybeShowWhatsNew() {
+  const overlay = document.getElementById('whatsNewOverlay');
+  const versionValue = document.getElementById('whatsNewVersion');
+  const continueBtn = document.getElementById('whatsNewContinueBtn');
+  const openChangesBtn = document.getElementById('whatsNewOpenChangesBtn');
+  const items = Array.isArray(ROLLCALC_WHATS_NEW_ITEMS)
+    ? ROLLCALC_WHATS_NEW_ITEMS
+    : [];
+
+  if (!overlay || !versionValue || !continueBtn || !openChangesBtn || items.length === 0) return;
+
+  let storedVersion = null;
+  try {
+    storedVersion = localStorage.getItem(ROLLCALC_LAST_SEEN_VERSION_KEY);
+  } catch (e) {
+    storedVersion = null;
+  }
+
+  if (!shouldShowWhatsNew(ROLLCALC_BUILD_VERSION, storedVersion)) return;
+
+  versionValue.textContent = ROLLCALC_BUILD_VERSION;
+  renderWhatsNewItems(items);
+  overlay.classList.remove('is-hidden');
+
+  continueBtn.addEventListener('click', () => {
+    markWhatsNewSeen(ROLLCALC_BUILD_VERSION);
+    overlay.classList.add('is-hidden');
+  }, { once: true });
+
+  openChangesBtn.addEventListener('click', () => {
+    markWhatsNewSeen(ROLLCALC_BUILD_VERSION);
+    window.location.href = {{ url_for('recent_changes')|tojson }};
+  }, { once: true });
+}
+
 document.addEventListener('DOMContentLoaded', () => {
   const overlay = document.getElementById('disclaimerOverlay');
   const checkbox = document.getElementById('disclaimerAccepted');
   const confirmBtn = document.getElementById('disclaimerConfirmBtn');
 
-  if (!overlay || !checkbox || !confirmBtn) return;
+  if (!overlay || !checkbox || !confirmBtn) {
+    maybeShowWhatsNew();
+    return;
+  }
 
   checkbox.addEventListener('change', () => {
     confirmBtn.disabled = !checkbox.checked;
@@ -1587,6 +1727,7 @@ document.addEventListener('DOMContentLoaded', () => {
   confirmBtn.addEventListener('click', () => {
     if (!checkbox.checked) return;
     overlay.classList.add('is-hidden');
+    maybeShowWhatsNew();
   });
 });
 </script>

templates/user_manual.html

@@ -3,8 +3,8 @@
 <head>
   <meta charset="UTF-8">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
-  <meta name="description" content="RollCalc User Manual">
-  <title>RollCalc User Manual</title>
+  <meta name="description" content="RollCalc {{ document_title }}">
+  <title>RollCalc {{ document_title }}</title>
   <style>
     * { box-sizing: border-box; margin: 0; padding: 0; }
     html { scroll-behavior: smooth; }
@@ -62,8 +62,8 @@
   <header class="help-header">
     <div class="help-header-inner">
       <div>
-        <h1>User Manual</h1>
-        <p>RollCalc technical user documentation</p>
+        <h1>{{ document_title }}</h1>
+        <p>{{ document_subtitle }}</p>
       </div>
       <nav class="help-nav" aria-label="Help navigation">
         <a href="{{ url_for('index') }}">Calculator</a>
@@ -75,7 +75,7 @@
   <main class="manual-shell">
     {% if render_error %}
       <section class="manual-error" role="alert">
-        <strong>User Manual unavailable</strong>
+        <strong>{{ error_title }}</strong>
         <p>{{ render_error }}</p>
       </section>
     {% else %}