feat: fee underpayment indicator + premium color on month tiles

- paid 200 zł (stawka 200): green (standard)
- paid 300 zł (stawka 300): teal (paid-premium)
- paid 200 zł (stawka 300): red outline + ! badge (underpaid)
Applied to both board/skladki and admin/fees views.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

templates/admin/fees.html

@@ -245,6 +245,7 @@
     }
 
     .month-cell.paid { background: var(--success); color: white; }
+    .month-cell.paid-premium { background: #0d9488; color: white; }
     .month-cell.partial { background: #60a5fa; color: white; }
     .month-cell.pending { background: var(--warning); color: white; }
     .month-cell.overdue { background: var(--error); color: white; }
@@ -481,12 +482,15 @@
                     {% for m in range(1, 13) %}
                     <td class="col-month">
                         {% set fee = cf.months.get(m) %}
+                        {% set expected = cf.expected_fees.get(m, 200) %}
+                        {% set underpaid = fee and fee.amount and fee.amount|int < expected %}
+                        {% set is_premium = fee and fee.status == 'paid' and expected >= 300 and fee.amount|int >= 300 %}
                         {% if fee %}
-                        <span class="month-cell {{ fee.status }}" title="{{ fee.status }}: wpłacono {{ fee.amount_paid|int }} z {{ fee.amount|int }} zł (stawka: {{ cf.expected_fees.get(m, 200) }} zł)" style="position:relative;">
+                        <span class="month-cell {% if is_premium %}paid-premium{% else %}{{ fee.status }}{% endif %}" title="{{ fee.status }}: wpłacono {{ fee.amount_paid|int }} z {{ fee.amount|int }} zł{% if underpaid %} ⚠ stawka powinna wynosić {{ expected }} zł{% endif %}{% if is_premium %} (stawka pełna 300 zł){% endif %}" style="position:relative;{% if underpaid %}outline:2px solid var(--error);outline-offset:-2px;{% endif %}">
-                            {{ m }}{% if fee.status == 'partial' %}<span class="partial-badge">{{ fee.amount_paid|int }}</span>{% endif %}
+                            {{ m }}{% if fee.status == 'partial' %}<span class="partial-badge">{{ fee.amount_paid|int }}</span>{% endif %}{% if underpaid %}<span style="position:absolute;top:-6px;right:-6px;background:var(--error);color:white;font-size:8px;font-weight:700;width:14px;height:14px;border-radius:50%;display:flex;align-items:center;justify-content:center;line-height:1;">!</span>{% endif %}
                         </span>
                         {% else %}
-                        <span class="month-cell empty" title="Brak rekordu (stawka: {{ cf.expected_fees.get(m, 200) }} zł)">-</span>
+                        <span class="month-cell empty" title="Brak rekordu (stawka: {{ expected }} zł)">-</span>
                         {% endif %}
                     </td>
                     {% endfor %}

templates/board/fees_readonly.html

@@ -125,6 +125,7 @@
     }
 
     .month-cell.paid { background: var(--success); color: white; }
+    .month-cell.paid-premium { background: #0d9488; color: white; }
     .month-cell.partial { background: #60a5fa; color: white; }
     .month-cell.pending { background: var(--warning); color: white; }
     .month-cell.overdue { background: var(--error); color: white; }
@@ -241,6 +242,8 @@
                     <th class="col-month">I</th><th class="col-month">II</th><th class="col-month">III</th><th class="col-month">IV</th><th class="col-month">V</th><th class="col-month">VI</th>
                     <th class="col-month">VII</th><th class="col-month">VIII</th><th class="col-month">IX</th><th class="col-month">X</th><th class="col-month">XI</th><th class="col-month">XII</th>
                     <th style="width:70px;font-size:9px;line-height:1.2;">Zaległ.<br><span style="font-weight:400;text-transform:none;">z lat poprz.</span></th>
+                    <th style="width:50px;font-size:9px;">Przyp.</th>
+                    <th style="width:60px;font-size:9px;">Wezwanie</th>
                 </tr>
             </thead>
             <tbody>
@@ -308,12 +311,15 @@
                     {% for m in range(1, 13) %}
                     <td class="col-month">
                         {% set fee = cf.months.get(m) %}
+                        {% set expected = cf.expected_fees.get(m, 200) %}
+                        {% set underpaid = fee and fee.amount and fee.amount|int < expected %}
+                        {% set is_premium = fee and fee.status == 'paid' and expected >= 300 and fee.amount|int >= 300 %}
                         {% if fee %}
-                        <span class="month-cell {{ fee.status }}" title="{{ fee.status }}: wpłacono {{ fee.amount_paid|int }} z {{ fee.amount|int }} zł (stawka: {{ cf.expected_fees.get(m, 200) }} zł)" style="position:relative;">
+                        <span class="month-cell {% if is_premium %}paid-premium{% else %}{{ fee.status }}{% endif %}" title="{{ fee.status }}: wpłacono {{ fee.amount_paid|int }} z {{ fee.amount|int }} zł{% if underpaid %} ⚠ stawka powinna wynosić {{ expected }} zł{% endif %}{% if is_premium %} (stawka pełna 300 zł){% endif %}" style="position:relative;{% if underpaid %}outline:2px solid var(--error);outline-offset:-2px;{% endif %}">
-                            {{ m }}{% if fee.status == 'partial' %}<span class="partial-badge">{{ fee.amount_paid|int }}</span>{% endif %}
+                            {{ m }}{% if fee.status == 'partial' %}<span class="partial-badge">{{ fee.amount_paid|int }}</span>{% endif %}{% if underpaid %}<span style="position:absolute;top:-6px;right:-6px;background:var(--error);color:white;font-size:8px;font-weight:700;width:14px;height:14px;border-radius:50%;display:flex;align-items:center;justify-content:center;line-height:1;">!</span>{% endif %}
                         </span>
                         {% else %}
-                        <span class="month-cell empty" title="Brak rekordu (stawka: {{ cf.expected_fees.get(m, 200) }} zł)">-</span>
+                        <span class="month-cell empty" title="Brak rekordu (stawka: {{ expected }} zł)">-</span>
                         {% endif %}
                     </td>
                     {% endfor %}