fix(process): name the Swift compile deadline (#6071)

Name REA_SWIFTC_COMPILE_TIMEOUT_MS, its effective milliseconds, the
1..2147483647 range, and the omitted 120000 ms default when a Darwin
ownership-helper compile times out. A change applies after REA restarts,
on the next ownership-helper compile.

Producer SIGXCPU and SIGXFSZ recovery says REA retains the tighter
inherited limit. Agent-visible fixed caps in this theme say this release
has no runtime override. Numbers are unchanged.

Refs #5910

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: morluto <morluto@users.noreply.github.com>

src/process/DarwinProcessRunTokenReader.ts

@@ -7,6 +7,7 @@ import { z } from "zod";
 
 import {
   DEFAULT_SWIFTC_COMPILE_TIMEOUT_MS,
+  MAX_PROVIDER_STARTUP_TIMEOUT_MS,
   providerStartupTimeoutSchema,
 } from "../config/providerStartupTimeout.js";
 import { err, ok, type Result } from "../domain/result.js";
@@ -105,7 +106,9 @@ export const SWIFTC_INTERRUPT = "SIGINT";
  * Swift SDK cache on the supported Intel macOS VM (about 88s), so compilation
  * stays bounded independently of short provider version probes. Invalid ambient
  * values fall back to the default; `parseConfig` still rejects them at CLI/MCP
- * admission.
+ * admission. The resolved value is captured when the reader is created.
+ * Production creates that reader from the launch environment at process start,
+ * so a change applies after REA restarts, on the next ownership-helper compile.
  */
 export const resolveSwiftcCompileTimeoutMs = (
   options: {
@@ -121,6 +124,10 @@ export const resolveSwiftcCompileTimeoutMs = (
   return parsed.success ? parsed.data : DEFAULT_SWIFTC_COMPILE_TIMEOUT_MS;
 };
 
+/** Name the existing swiftc deadline when a helper compile times out. */
+export const swiftcCompileTimeoutRecovery = (timeoutMs: number): string =>
+  `The effective REA_SWIFTC_COMPILE_TIMEOUT_MS value is ${String(timeoutMs)} ms (integer range 1..${String(MAX_PROVIDER_STARTUP_TIMEOUT_MS)}; omitted default ${String(DEFAULT_SWIFTC_COMPILE_TIMEOUT_MS)} ms). Set it in the environment that starts REA and restart REA; the next ownership-helper compile uses the new value.`;
+
 /** Bound on compiler diagnostics embedded in the inspection failure text. */
 const STDERR_EXCERPT_LIMIT = 512;
 
@@ -272,8 +279,11 @@ const compilerOutcomeDescription = (
   if (outcome === undefined) return `compiler result: ${String(fallbackCode)}`;
   if (outcome.outcome === "exited")
     return `compiler result: exit code ${String(outcome.code)}`;
-  if (outcome.outcome === "timed_out")
-    return `compiler result: timed out after ${String(outcome.timeoutMs)} ms`;
+  if (outcome.outcome === "timed_out") {
+    if (outcome.timeoutMs === undefined)
+      return "compiler result: timed out. The effective REA_SWIFTC_COMPILE_TIMEOUT_MS value was not reported.";
+    return `compiler result: timed out after ${String(outcome.timeoutMs)} ms. ${swiftcCompileTimeoutRecovery(outcome.timeoutMs)}`;
+  }
   if (outcome.outcome === "signaled")
     return `compiler result: stopped by signal ${outcome.signal ?? "an unknown signal"}`;
   return `compiler result: ${String(outcome.code)}`;
@@ -302,8 +312,13 @@ const compilerInspectionError = (
     stderr.truncated ||
     outcome?.stderrTruncated === true ||
     outcome?.outputTruncated === true;
+  const truncationNote = !truncated
+    ? ""
+    : stderr.truncated
+      ? `… [diagnostics truncated at ${String(STDERR_EXCERPT_LIMIT)} bytes; this release has no runtime override]`
+      : "… [diagnostics truncated; this release has no runtime override]";
   const suffix = diagnostics
-    ? `: ${diagnostics}${truncated ? "… [diagnostics truncated]" : ""}`
+    ? `: ${diagnostics}${truncationNote}`
     : outcome === undefined
       ? `: ${cause instanceof Error ? cause.message : String(cause)}`
       : ": no compiler diagnostics were captured";