fix(javascript): report available parent result budget in coverage limits (#1915)

* fix(javascript): size the future static reserve by remaining sources

The parent reserved 80% of its result budget for future static facts
whenever any source remained, so one tiny later file could discard an
earlier file's completed semantic graph. Reserve at most one bounded
static checkpoint's retained size per remaining source, within the same
shared pool, so many remaining sources keep the previous protection.
Parent-budget rejections now report the effective admission budget and
explain that the CLI/MCP process heap, not max_heap_mb, bounds them.

Refs #1911

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(javascript): make parent budget remediation and its test runtime-aware

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(javascript): suggest a concrete parent heap size in remediation

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(javascript): let parent budget rejections state their retained facts

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

src/domain/javascript/javascriptAnalysisResourceControls.ts

@@ -18,6 +18,7 @@ export const javaScriptAnalysisCoverageLimits = (
     "worker_process_memory_limit_bytes",
     "worker_timeout_ms",
     "parent_result_budget_bytes",
+    "parent_available_result_budget_bytes",
     "semantic_result_budget_bytes",
     "transfer_record_bytes",
     "transfer_file_bytes",