Initial portal commit: landing + 9 AI-powered apps

Apps:
- dwg-rooms: extract room numbers from DWG/DXF
- dwg-counting: count symbols in PDF drawings (OpenCV template matching)
- contract-check: review PDF contracts against a checklist (Claude vision + Tesseract OCR fallback)
- email-drafter: bullet notes → polished Czech/English business emails
- invoice-extractor: PDF/image invoice → structured data → Excel
- translator: Czech-first translator across 19 languages with tone control
- vv-check: find inconsistent unit prices across VV sheets in one workbook
- vv-compare: diff original vs new VV files (changes / added / removed)
- feature-request: portal users submit ideas + sample files

Infrastructure:
- LiteLLM gateway with per-app virtual keys + budgets
- Langfuse observability
- Geist font, shared theme, cross-subdomain back link + theme sync via cookie/URL
- Caddy reverse proxy on *.klas.chat

vv-compare/static/extra.css

@@ -0,0 +1,149 @@
+/* VV compare specific */
+
+.processing-sub {
+  font-size: 13px;
+  color: var(--text-tertiary);
+  margin: 8px auto 0;
+  max-width: 400px;
+}
+
+.dual-drop {
+  display: flex;
+  align-items: stretch;
+  gap: 14px;
+  margin-bottom: 18px;
+}
+.drop-half { flex: 1; display: flex; flex-direction: column; gap: 6px; }
+.drop-label {
+  font-size: 11px;
+  font-weight: 600;
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+  color: var(--text-tertiary);
+  padding-left: 4px;
+}
+.drop-zone-mini {
+  flex: 1;
+  border: 1.5px dashed var(--border-strong);
+  border-radius: var(--radius-lg);
+  background: var(--bg-secondary);
+  padding: 32px 18px;
+  text-align: center;
+  cursor: pointer;
+  transition: border-color .15s, background .15s;
+  min-height: 140px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+.drop-zone-mini:hover { border-color: var(--primary); }
+.drop-zone-mini.drag-over { border-color: var(--primary); background: color-mix(in srgb, var(--primary) 5%, var(--bg-secondary)); }
+.drop-zone-mini.has-file {
+  border-style: solid;
+  border-color: var(--primary);
+  background: color-mix(in srgb, var(--primary) 4%, var(--bg-secondary));
+}
+.drop-arrow {
+  align-self: center;
+  font-size: 22px;
+  color: var(--text-quaternary);
+  font-weight: 200;
+  padding: 0 4px;
+}
+@media (max-width: 640px) {
+  .dual-drop { flex-direction: column; }
+  .drop-arrow { transform: rotate(90deg); padding: 4px 0; }
+}
+
+.run-row {
+  display: flex; align-items: center; gap: 14px;
+  padding-top: 16px; border-top: 1px solid var(--border-default);
+  flex-wrap: wrap;
+}
+.btn-lg { padding: 12px 26px; font-size: 14px; font-weight: 600; }
+.run-hint { font-size: 13px; color: var(--text-tertiary); }
+
+.recap-cards {
+  display: grid;
+  grid-template-columns: repeat(3, 1fr);
+  gap: 14px;
+  margin: 16px 0 22px;
+}
+.recap-card {
+  background: var(--card);
+  border: 1px solid var(--border-default);
+  border-radius: var(--radius-lg);
+  padding: 18px 22px;
+  border-left: 4px solid #94a3b8;
+}
+.recap-card.recap-changed { border-left-color: #f59e0b; }
+.recap-card.recap-added   { border-left-color: #22c55e; }
+.recap-card.recap-removed { border-left-color: #ef4444; }
+.recap-label {
+  font-size: 11px;
+  font-weight: 600;
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+  color: var(--text-tertiary);
+  margin-bottom: 6px;
+}
+.recap-value {
+  font-size: 32px;
+  font-weight: 600;
+  color: var(--text-primary);
+  font-variant-numeric: tabular-nums;
+  line-height: 1;
+}
+
+.per-sheet {
+  background: var(--card);
+  border: 1px solid var(--border-default);
+  border-radius: var(--radius-lg);
+  padding: 16px 18px;
+  overflow-x: auto;
+}
+.per-sheet table { width: 100%; border-collapse: collapse; font-size: 13px; }
+.per-sheet th, .per-sheet td {
+  padding: 8px 10px;
+  border-bottom: 1px solid var(--border-default);
+  text-align: left;
+}
+.per-sheet th {
+  font-size: 11px;
+  font-weight: 600;
+  text-transform: uppercase;
+  letter-spacing: 0.04em;
+  color: var(--text-tertiary);
+  background: var(--bg-secondary);
+}
+.per-sheet td.num { text-align: right; font-variant-numeric: tabular-nums; }
+.per-sheet .pill {
+  display: inline-block;
+  padding: 1px 7px;
+  border-radius: 999px;
+  font-weight: 600;
+  font-variant-numeric: tabular-nums;
+}
+.per-sheet .pill.changed { background: rgba(245,158,11,0.15); color: #b45309; }
+.per-sheet .pill.added   { background: rgba(34,197,94,0.15); color: #15803d; }
+.per-sheet .pill.removed { background: rgba(239,68,68,0.15); color: #b91c1c; }
+.per-sheet .pill.zero    { background: var(--bg-tertiary); color: var(--text-quaternary); }
+
+/* Back link */
+.back-link {
+  display: inline-flex; align-items: center; gap: 6px;
+  padding: 6px 12px 6px 10px; border-radius: 8px;
+  font-size: 13px; font-weight: 500; color: var(--text-tertiary);
+  text-decoration: none; border: 0.5px solid var(--border-default);
+  background: var(--bg-primary); flex-shrink: 0;
+  transition: color .15s, border-color .15s, background .15s;
+}
+.back-link:hover {
+  color: var(--primary); border-color: var(--primary);
+  background: color-mix(in srgb, var(--primary) 6%, var(--bg-primary));
+}
+.back-link svg { opacity: 0.8; }
+@media (max-width: 640px) {
+  .back-link span { display: none; }
+  .back-link { padding: 6px; }
+}