🎨 Palette: Improve table accessibility and typography

.jules/palette.md

@@ -19,3 +19,7 @@
 ## 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.
+
+## 2026-07-22 - Accessibility for HTML reports
+**Learning:** Generating semantic HTML tables for data reports is important for screen reader compatibility.
+**Action:** Applied <th scope="row"> for first identifying column, font-variant-numeric: tabular-nums for styling, and separated CSS th matching between thead th and tbody th.

python/fast_mlsirm/report.py

@@ -317,10 +317,12 @@ 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_list = []
+        for i, column in enumerate(columns):
+            tag = 'th scope="row"' if i == 0 else "td"
+            close_tag = "th" if i == 0 else "td"
+            cells_list.append(f"<{tag}>{escape(_format_value(row.get(column, '')))}</{close_tag}>")
+        cells = "".join(cells_list)
         body_rows.append(f"<tr>{cells}</tr>")
 
     note = ""
@@ -679,20 +681,26 @@ def _css() -> str:
   border: 0;
 }
 
-th,
+thead th,
+tbody th,
 td {
   padding: 10px 12px;
   text-align: left;
   border-bottom: 1px solid var(--line);
   white-space: nowrap;
+  font-variant-numeric: tabular-nums;
 }
 
-th {
+thead th {
   background: #f1f4ef;
   color: #2f3437;
   font-size: 0.8rem;
 }
 
+tbody th {
+  font-weight: normal;
+}
+
 tr:last-child td {
   border-bottom: 0;
 }