fix(go): adults template — emit markup that the lifted CSS expects

The lifted-from-Python app.css already styles .list-container/.list-item,
.unmatched-row, .balance-pos/.balance-neg, and cell-{status}; the M6.2
template invented .credits-list / .unmatched-table / .balance-cell that
had no rules, so those sections rendered unstyled.

- Credits / Debts: <ul><li> → <div class="list-container"><div class="list-item">
  <span class="list-item-name"> + <span class="list-item-val"> (debts red inline).
- Unmatched: <table> → <div class="list-container"> + <div class="unmatched-row">.
- Balance cell: balance-pos / balance-neg with style="position: relative;";
  Pay-All button now lives inside it (no separate trailing column).
- Total row: cell-{status} + caption span "received / expected" + bold/dark inline styles.
- Drop redundant .cell wrapper class; balance value drops trailing "CZK".
- Section headings: "Credits (Advance Payments / Surplus)" + "Debts (Missing Payments)".
- Source links: <div class="description"> block under h1 (was at page bottom).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog
 
+## 2026-05-08 10:15 CEST — fix(go): adults template — use lifted CSS classes for visual parity
+
+- Use existing `.balance-pos` / `.balance-neg` (drop invented `balance-cell` / `balance-negative`); Pay-All button now lives inside the balance cell with `position: relative` (matches Python; no separate trailing column).
+- Credits / Debts / Unmatched sections rewritten from `<ul>` / `<table>` to `<div class="list-container"><div class="list-item">…` / `<div class="unmatched-row">…` so the lifted CSS actually applies.
+- Section headings get the descriptive Python text: "Credits (Advance Payments / Surplus)", "Debts (Missing Payments)".
+- Source links moved from page bottom to a `<div class="description">` block under the h1, matching Python's "Source: Attendance Sheet | Payments Ledger".
+- Total row uses `cell-{{Status}}` plus the small "received / expected" caption span and Python's inline-styled bold/dark background.
+- Drop the redundant `class="cell"` wrapper; debts amount turns red via inline style; balance value drops the trailing "CZK".
+
 ## 2026-05-08 01:09 CEST — feat(go): M6.2 — adults page (table, filters, Pay buttons)
 
 - `go/internal/web/api/handler.go`: extracted `ServeAdults` body into `AssembleAdults(ctx)` — shared by the JSON API route and the new HTML handler.