refactor(javascript): own coverage facts and reuse block prefixes

Separate syntax, semantic uncertainty, examination limits and observed Electron applicability at the static producer, then preserve them through worker, graph and retained/inline summary views. Derive the established parse_status from the same facts and leave historical measurements unknown. Give semantic resource-limit classifications one schema owner.

Replace repeated block-prefix searches and copies with collector-scoped syntax indexes. Keep invocation environments separate, charge indexing/replay to the existing work budget and yield during prefix work. Remove the superseded synchronous collector entrypoint.

Validated producer, worker, CLI/MCP, historical and partial-coverage regressions, plus actual cancellation during indexing. Bounded authored 128/256-call controls preserved all prior facts while replacing repeated search/copy work with one index pass; this is not a throughput or agent-token benchmark.

src/domain/javascript/javascriptStaticAnalysisHelpers.ts

@@ -23,10 +23,17 @@ import {
   compareUnicodeCodePoints,
   compositeKey,
 } from "../unicodeCodePointOrder.js";
+import { unexaminedJavaScriptStaticCoverage } from "./javascriptStaticCoverage.js";
 
 /** Explicit result for source text that Babel cannot parse. */
 export const failedJavaScriptStaticAnalysis = (): JavaScriptStaticAnalysis => ({
   parse_status: "failed",
+  analysis_coverage: {
+    ...unexaminedJavaScriptStaticCoverage(
+      "JavaScript source could not be parsed.",
+    ),
+    syntax: { status: "failed", error_count: null },
+  },
   parse_error_count: 1,
   visited_ast_nodes: 0,
   references: [],