refactor: unify declare block scanning between CLI and client

Introduce `scanDeclareBlocks` in `declare-parser.ts` to provide a
single source of truth for parsing `role=declare` blocks. This
replaces redundant scanning logic in both the CLI and the journal
completions.

Also remove unused `dice.ts` and `spark-scanner.ts` files.

src/cli/completions/block-processor.ts

@@ -7,7 +7,7 @@
 
 import { posix } from "path";
 import { createHash } from "crypto";
-import { parseDeclareCsv, type VarDeclaration, type TagModifier } from "./declare-parser.js";
+import { scanDeclareBlocks, type VarDeclaration, type TagModifier } from "./declare-parser.js";
 import {
   FENCED_BLOCK_RE,
   parseBlockAttrs,
@@ -86,13 +86,9 @@ export function processBlocks(
       // ---- Dispatch by role ----
 
       if (attrs.role === "declare") {
-        try {
-          const result = parseDeclareCsv(body, fileRelativePath);
-          blocks.declarations.push(...result.variables);
-          blocks.tagModifiers.push(...result.tagModifiers);
-        } catch (e) {
-          console.warn(`[block-processor] ${fileRelativePath}: ${e}`);
-        }
+        const result = scanDeclareBlocks(_match, fileRelativePath);
+        blocks.declarations.push(...result.variables);
+        blocks.tagModifiers.push(...result.tagModifiers);
       }
 
       if (attrs.role === "file") {