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/components/journal/declare-parser.ts

@@ -3,7 +3,8 @@
  */
 
 export {
-  parseDeclareCsv,
+  parseDeclare,
+  declareSchema,
   type VarDeclaration,
   type TagModifier,
   type DeclareResult,

src/components/journal/index.ts

@@ -56,7 +56,7 @@ export type { ParsedInput, CompletionItem } from "./command-parser";
 export { buildCompletions } from "./command-completions";
 export type { CompletionsContext } from "./command-completions";
 export { VariableView } from "./VariableView";
-export { parseDeclareCsv } from "./declare-parser";
+export { parseDeclare, declareSchema } from "./declare-parser";
 export type { VarDeclaration, TagModifier } from "./declare-parser";
 export { evaluateExpression, expressionIsTag, exprValueToString } from "./variable-expression";
 export type { EvalContext, EvalResult, ExprValue } from "./variable-expression";