test: introduce planner-backed test runner, stabilize local builds (#54650)

* test: stabilize ci and local vitest workers

* test: introduce planner-backed test runner

* test: address planner review follow-ups

* test: derive planner budgets from host capabilities

* test: restore planner filter helper import

* test: align planner explain output with execution

* test: keep low profile as serial alias

* test: restrict explicit planner file targets

* test: clean planner exits and pnpm launch

* test: tighten wrapper flag validation

* ci: gate heavy fanout on check

* test: key shard assignments by unit identity

* ci(bun): shard vitest lanes further

* test: restore ci overlap and stabilize planner tests

* test: relax planner output worker assertions

* test: reset plugin runtime state in optional tools suite

* ci: split macos node and swift jobs

* test: honor no-isolate top-level concurrency budgets

* ci: fix macos swift format lint

* test: cap max-profile top-level concurrency

* ci: shard macos node checks

* ci: use four macos node shards

* test: normalize explain targets before classification

scripts/test-planner/vitest-args.mjs

@@ -0,0 +1,74 @@
+export const OPTION_TAKES_VALUE = new Set([
+  "-t",
+  "-c",
+  "-r",
+  "--testNamePattern",
+  "--config",
+  "--root",
+  "--dir",
+  "--reporter",
+  "--outputFile",
+  "--pool",
+  "--execArgv",
+  "--vmMemoryLimit",
+  "--maxWorkers",
+  "--environment",
+  "--shard",
+  "--changed",
+  "--sequence",
+  "--inspect",
+  "--inspectBrk",
+  "--testTimeout",
+  "--hookTimeout",
+  "--bail",
+  "--retry",
+  "--diff",
+  "--exclude",
+  "--project",
+  "--slowTestThreshold",
+  "--teardownTimeout",
+  "--attachmentsDir",
+  "--mode",
+  "--api",
+  "--browser",
+  "--maxConcurrency",
+  "--mergeReports",
+  "--configLoader",
+  "--experimental",
+]);
+
+export const SINGLE_RUN_ONLY_FLAGS = new Set(["--coverage", "--outputFile", "--mergeReports"]);
+
+export const parsePassthroughArgs = (args = []) => {
+  const fileFilters = [];
+  const optionArgs = [];
+  let consumeNextAsOptionValue = false;
+
+  for (const arg of args) {
+    if (consumeNextAsOptionValue) {
+      optionArgs.push(arg);
+      consumeNextAsOptionValue = false;
+      continue;
+    }
+    if (arg === "--") {
+      optionArgs.push(arg);
+      continue;
+    }
+    if (typeof arg === "string" && arg.startsWith("-")) {
+      optionArgs.push(arg);
+      consumeNextAsOptionValue = !arg.includes("=") && OPTION_TAKES_VALUE.has(arg);
+      continue;
+    }
+    fileFilters.push(arg);
+  }
+
+  return { fileFilters, optionArgs };
+};
+
+export const countExplicitEntryFilters = (entryArgs) => {
+  const { fileFilters } = parsePassthroughArgs(entryArgs.slice(2));
+  return fileFilters.length > 0 ? fileFilters.length : null;
+};
+
+export const getExplicitEntryFilters = (entryArgs) =>
+  parsePassthroughArgs(entryArgs.slice(2)).fileFilters;