feat: TKB shift scheduler — personnel shift planning web app

Full rewrite of METRO HMG for TKB tunnel department:
- People-based grid (18 TKB + 5 IT), year-long calendar
- Color-coded shift values (4/6/8/12/A/B/D/N/U/O)
- Drag-and-drop cells, multi-cell selection (click/ctrl/shift/drag)
- Right-click context menu with color palette
- Tunnel closure + Metro + D8 info rows (toggleable)
- Czech holidays highlighted with names
- PDF export (2-page A4 landscape, DejaVu font for Czech chars)
- Improvement proposals system
- Sticky headers (vertical + horizontal scroll)
- Cell value filter toggles in legend

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

web/import_excel.py

@@ -0,0 +1,166 @@
+#!/usr/bin/env python3
+"""Parse Excel schedule file and output JSON to stdout."""
+import json
+import sys
+from datetime import date
+import openpyxl
+
+filepath = sys.argv[1]
+wb = openpyxl.load_workbook(filepath, data_only=True)
+ws = wb.active
+
+# Also load with styles for comments
+wb2 = openpyxl.load_workbook(filepath)
+ws2 = wb2.active
+
+# --- Build dayIndex from row 9 (months) and row 11 (days) ---
+month_starts = {}
+for col in range(7, 300):
+    val = ws.cell(row=9, column=col).value
+    if val is not None and hasattr(val, 'month'):
+        month_starts[col] = (val.year, val.month)
+
+if not month_starts:
+    print(json.dumps({"error": "No month data found in row 9"}), file=sys.stderr)
+    sys.exit(1)
+
+day_index = []
+for col in range(7, 300):
+    day_val = ws.cell(row=11, column=col).value
+    if day_val is None:
+        continue
+    day_num = int(day_val)
+
+    current_month = None
+    for mcol in sorted(month_starts.keys(), reverse=True):
+        if col >= mcol:
+            current_month = month_starts[mcol]
+            break
+
+    if current_month is None:
+        continue
+
+    year, month = current_month
+    idx = col - 7
+
+    try:
+        d = date(year, month, day_num)
+        is_weekend = d.weekday() >= 5
+        week = d.isocalendar()[1]
+    except ValueError:
+        is_weekend = False
+        week = 0
+
+    day_index.append({
+        "idx": idx,
+        "day": day_num,
+        "month": month,
+        "year": year,
+        "week": week,
+        "weekend": is_weekend,
+    })
+
+# --- Extract station data ---
+valid_idx = set(d["idx"] for d in day_index)
+stations = []
+
+for row in range(13, 40):
+    code = ws.cell(row=row, column=1).value
+    name = ws.cell(row=row, column=2).value or ""
+    server = ws.cell(row=row, column=3).value or ""
+
+    if not code:
+        continue
+
+    data = {}
+    for col in range(7, 300):
+        idx = col - 7
+        if idx not in valid_idx:
+            continue
+        val = ws.cell(row=row, column=col).value
+        if val is None:
+            continue
+        if isinstance(val, str) and val.strip() == "":
+            continue
+
+        entry = {}
+        if isinstance(val, (int, float)):
+            entry["v"] = int(val) if val == int(val) else val
+        else:
+            v = str(val).strip()
+            # Normalize: lowercase z -> uppercase Z
+            if v == 'z':
+                v = 'Z'
+            entry["v"] = v
+
+        data[str(idx)] = entry
+
+    stations.append({
+        "code": str(code).strip(),
+        "name": str(name).strip(),
+        "server": str(server).strip(),
+        "duration": None,
+        "data": data,
+    })
+
+# --- Extract DEN row comments ---
+day_comments = []
+for col in range(7, 300):
+    cell = ws2.cell(row=11, column=col)
+    if cell.comment:
+        idx = col - 7
+        if idx not in valid_idx:
+            continue
+        text = cell.comment.text
+        # Extract actual comment from threaded format (Czech or English)
+        if "Komentář:\n" in text:
+            note = text.split("Komentář:\n")[-1].strip()
+        elif "Comment:\n" in text:
+            note = text.split("Comment:\n")[-1].strip()
+        else:
+            note = text.strip()
+        if note:
+            day_comments.append({"dayIdx": idx, "text": note})
+
+# --- Extract cell comments from data rows ---
+cell_comments = []
+for row in range(13, 40):
+    code = ws2.cell(row=row, column=1).value
+    if not code:
+        continue
+    code = str(code).strip()
+    for col in range(7, 300):
+        cell = ws2.cell(row=row, column=col)
+        if cell.comment:
+            idx = col - 7
+            if idx not in valid_idx:
+                continue
+            text = cell.comment.text
+            if "Komentář:\n" in text:
+                note = text.split("Komentář:\n")[-1].strip()
+            elif "Comment:\n" in text:
+                note = text.split("Comment:\n")[-1].strip()
+            else:
+                note = text.strip()
+            if note:
+                cell_comments.append({"stationCode": code, "dayIdx": idx, "text": note})
+
+# Deduplicate dayIndex — keep only first occurrence of each date
+seen_dates = set()
+deduped_day_index = []
+for d in day_index:
+    date_key = (d["year"], d["month"], d["day"])
+    if date_key not in seen_dates:
+        seen_dates.add(date_key)
+        deduped_day_index.append(d)
+day_index = deduped_day_index
+
+result = {
+    "dayIndex": day_index,
+    "stations": stations,
+    "obstacles": [],
+    "dayComments": day_comments,
+    "cellComments": cell_comments,
+}
+
+print(json.dumps(result, ensure_ascii=False))