feat(cli): Complete the check rule catalog

Add D002 (malformed attribute blocks), R004 (skipped declare rows), and V001-V005 (CSV data files). CSV checks run once per referenced file and also cover inline spark-table bodies.

Generate docs/reference.md from the known.ts catalog via npm run gen:reference, and add drift guards asserting the catalog matches the customElement call sites and the committed reference.

src/cli/validate/checks/roles.ts

@@ -2,6 +2,7 @@
  * Code-block role checks.
  */
 
+import { parse } from "csv-parse/browser/esm/sync";
 import { parseDeclareCsv } from "../../completions/declare-parser.js";
 import { diagnosticAt } from "../diagnostics.js";
 import { ELEMENT_NAMES, KNOWN_ROLES } from "../known.js";
@@ -73,6 +74,50 @@ function checkDeclare(fence: RawFence, ctx: CheckContext): void {
         "role=declare needs `key` and `expr` columns; `tag` and `threshold` are optional",
       ),
     );
+    return;
+  }
+
+  checkDeclareRows(fence, ctx);
+}
+
+/**
+ * R004 — `parseDeclareCsv` silently skips rows with an empty `key` or `expr`.
+ * Re-parse with line info so the skipped row can be localized.
+ */
+function checkDeclareRows(fence: RawFence, ctx: CheckContext): void {
+  const { source, file, sink } = ctx;
+  let records: Array<{ record: Record<string, string>; info: { lines: number } }>;
+  try {
+    records = parse(fence.body, {
+      columns: true,
+      trim: true,
+      skipEmptyLines: true,
+      info: true,
+    }) as unknown as typeof records;
+  } catch {
+    return; // R003 already reported the parse failure
+  }
+  if (records.length === 0) return;
+
+  const headers = Object.keys(records[0].record).map((h) => h.toLowerCase());
+  if (!headers.includes("key") || !headers.includes("expr")) return;
+
+  const baseLine = source.position(fence.bodyOffset).line;
+  for (const { record, info } of records) {
+    const key = record.key ?? "";
+    const expr = record.expr ?? "";
+    if (key && expr) continue;
+    sink.report(
+      diagnosticAt(
+        file,
+        source,
+        source.lineStart(baseLine + info.lines - 1),
+        "TTTK-R004",
+        "warning",
+        `declare row skipped: ${!key ? "empty key" : "empty expr"}`,
+        "every declare row needs both a key and an expression",
+      ),
+    );
   }
 }