🎨 Palette: Improve table accessibility and alignment

.jules/palette.md

@@ -19,3 +19,6 @@
 ## 2024-07-13 - CLI Debugging Stack Traces
 **Learning:** Adding a `FAST_MLSIRM_DEBUG` bypass to user-friendly `try/except` blocks is crucial for DX. Otherwise, unexpected runtime errors during development will be swallowed into generic stderr messages, hiding the stack trace needed to actually fix the bug.
 **Action:** When adding `try-except` blocks to Python CLI subcommands to improve Developer Experience (DX) by preventing raw tracebacks for users, include a debug bypass (e.g., `if os.environ.get("FAST_MLSIRM_DEBUG"): raise`) in *all* catch blocks (including `RuntimeError` and `Exception`) to ensure tracebacks aren't swallowed during local development and debugging.
+## 2026-07-18 - Improve Table Accessibility and Alignment
+**Learning:** When generating HTML data tables, using `<th scope="row">` for the first identifying column improves screen reader accessibility. Additionally, applying `font-variant-numeric: tabular-nums;` to table cells ensures numbers align properly in columns.
+**Action:** Use `<th scope="row">` for row headers and `font-variant-numeric: tabular-nums` for numeric data cells in tabular data representations.

python/fast_mlsirm/report.py

@@ -317,10 +317,13 @@ def _table(rows: list[dict[str, Any]], *, label: str, limit: int = 12) -> str:
     columns = _columns(rows)
     body_rows = []
     for row in rows[:limit]:
-        cells = "".join(
-            f"<td>{escape(_format_value(row.get(column, '')))}</td>"
-            for column in columns
-        )
+        cells = ""
+        for i, column in enumerate(columns):
+            val = escape(_format_value(row.get(column, "")))
+            if i == 0:
+                cells += f'<th scope="row">{val}</th>'
+            else:
+                cells += f"<td>{val}</td>"
         body_rows.append(f"<tr>{cells}</tr>")
 
     note = ""
@@ -687,13 +690,23 @@ def _css() -> str:
   white-space: nowrap;
 }
 
-th {
+td,
+tbody th {
+  font-variant-numeric: tabular-nums;
+}
+
+thead th {
   background: #f1f4ef;
   color: #2f3437;
   font-size: 0.8rem;
 }
 
-tr:last-child td {
+tbody th {
+  font-weight: normal;
+}
+
+tr:last-child td,
+tr:last-child th {
   border-bottom: 0;
 }