feat(declare)!: parse role=declare blocks as YAML

Replace the tag/threshold/key/expr CSV body with YAML `vars:` and
`tags:` maps. `parseDeclare` validates the body with an exported Zod
schema and returns the same declaration and modifier shapes the
reactivity engine already consumes.

The breaking rename from `parseDeclareCsv` updates the registry, the
journal re-exports, and the `tttk check` role checks, where R003 now
reports schema errors with their path and R004 warns when a block
declares nothing.

src/cli/validate/checks/roles.ts

@@ -2,8 +2,7 @@
  * Code-block role checks.
  */
 
-import { parse } from "csv-parse/browser/esm/sync";
-import { parseDeclareCsv } from "../../completions/declare-parser.js";
+import { parseDeclare, type DeclareResult } from "../../completions/declare-parser.js";
 import { diagnosticAt } from "../diagnostics.js";
 import { ELEMENT_NAMES, KNOWN_ROLES } from "../known.js";
 import type { RawFence } from "../scan.js";
@@ -60,8 +59,25 @@ function checkSparkTable(fence: RawFence, ctx: CheckContext): void {
 
 function checkDeclare(fence: RawFence, ctx: CheckContext): void {
   const { source, file, sink } = ctx;
+
+  if (/^csv$/i.test(fence.lang)) {
+    sink.report(
+      diagnosticAt(
+        file,
+        source,
+        fence.offset,
+        "TTTK-R003",
+        "error",
+        "role=declare blocks are YAML, not CSV",
+        "use ```yaml role=declare with `vars:` and `tags:` maps",
+      ),
+    );
+    return;
+  }
+
+  let result: DeclareResult;
   try {
-    parseDeclareCsv(fence.body, file);
+    result = parseDeclare(fence.body);
   } catch (error) {
     sink.report(
       diagnosticAt(
@@ -71,51 +87,22 @@ function checkDeclare(fence: RawFence, ctx: CheckContext): void {
         "TTTK-R003",
         "error",
         error instanceof Error ? error.message : String(error),
-        "role=declare needs `key` and `expr` columns; `tag` and `threshold` are optional",
+        "role=declare is YAML: `vars:` maps `$name` to an expression; `tags:` maps a tag name to threshold maps",
       ),
     );
     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;
+  if (result.variables.length === 0 && result.tagModifiers.length === 0) {
     sink.report(
       diagnosticAt(
         file,
         source,
-        source.lineStart(baseLine + info.lines - 1),
+        fence.offset,
         "TTTK-R004",
         "warning",
-        `declare row skipped: ${!key ? "empty key" : "empty expr"}`,
-        "every declare row needs both a key and an expression",
+        "role=declare block declares nothing",
+        "add a `vars:` or `tags:` mapping; the block has no effect",
       ),
     );
   }