feat(voyage): add phase-signal-resolver helper for v5.1.1 wiring

plugins/voyage/lib/profiles/phase-signal-resolver.mjs

@@ -0,0 +1,86 @@
+// lib/profiles/phase-signal-resolver.mjs
+// v5.1.1 — extract per-phase signal from a brief's frontmatter.
+//
+// Decision A wiring: commands invoke this helper via Bash CLI shim
+// (`node lib/profiles/phase-signal-resolver.mjs --brief <path> --phase <name> --json`)
+// to obtain the {effort, model} pair for a specific pipeline phase.
+//
+// Sole source of truth for PHASE_SIGNAL_PHASES + EFFORT_LEVELS is
+// lib/validators/brief-validator.mjs — re-imported here so the helper
+// cannot drift from the schema validator.
+
+import { readFileSync, existsSync } from 'node:fs';
+import { parseDocument } from '../util/frontmatter.mjs';
+import { PHASE_SIGNAL_PHASES, EFFORT_LEVELS } from '../validators/brief-validator.mjs';
+
+/**
+ * Resolve a brief's phase_signal entry for one phase.
+ *
+ * @param {object|null} briefFrontmatter  Parsed YAML frontmatter dict (or null/undefined).
+ * @param {string} phase                  One of PHASE_SIGNAL_PHASES; anything else returns null.
+ * @returns {{effort?: string, model?: string} | null}
+ *
+ * Never throws. Returns null on:
+ *  - Falsy / non-object frontmatter
+ *  - phase not in PHASE_SIGNAL_PHASES (e.g. 'brief' or 'continue')
+ *  - Missing phase_signals array
+ *  - No entry for the requested phase
+ *
+ * Returns partial `{effort}` (with `model: undefined`) when the signal omits model.
+ */
+export function resolvePhaseSignal(briefFrontmatter, phase) {
+  if (!briefFrontmatter || typeof briefFrontmatter !== 'object') return null;
+  if (typeof phase !== 'string' || !PHASE_SIGNAL_PHASES.includes(phase)) return null;
+  const signals = briefFrontmatter.phase_signals;
+  if (!Array.isArray(signals)) return null;
+  for (const entry of signals) {
+    if (entry && typeof entry === 'object' && entry.phase === phase) {
+      const out = {};
+      if ('effort' in entry && EFFORT_LEVELS.includes(entry.effort)) out.effort = entry.effort;
+      if ('model' in entry) out.model = entry.model;
+      return out;
+    }
+  }
+  return null;
+}
+
+/**
+ * Convenience wrapper: read a brief file, parse, and resolve a single phase.
+ * Returns null on any read or parse failure (graceful degradation).
+ */
+export function resolvePhaseSignalFromFile(briefPath, phase) {
+  if (typeof briefPath !== 'string' || briefPath.length === 0) return null;
+  if (!existsSync(briefPath)) return null;
+  let text;
+  try { text = readFileSync(briefPath, 'utf-8'); } catch { return null; }
+  const doc = parseDocument(text);
+  if (!doc || !doc.valid) return null;
+  const fm = doc.parsed && doc.parsed.frontmatter;
+  return resolvePhaseSignal(fm, phase);
+}
+
+// CLI shim — mirrors lib/validators/brief-validator.mjs:168 pattern.
+if (import.meta.url === `file://${process.argv[1]}`) {
+  const args = process.argv.slice(2);
+  const getArg = (name) => {
+    const i = args.indexOf(name);
+    return i >= 0 && i + 1 < args.length ? args[i + 1] : null;
+  };
+  const briefPath = getArg('--brief');
+  const phase = getArg('--phase');
+  if (!briefPath || !phase) {
+    process.stderr.write('Usage: phase-signal-resolver.mjs --brief <path> --phase <name> [--json]\n');
+    process.exit(2);
+  }
+  const result = resolvePhaseSignalFromFile(briefPath, phase);
+  if (args.includes('--json')) {
+    process.stdout.write(JSON.stringify(result) + '\n');
+  } else if (result === null) {
+    process.stdout.write('null\n');
+  } else {
+    const effort = 'effort' in result ? result.effort : '';
+    const model = 'model' in result ? result.model : '';
+    process.stdout.write(`effort=${effort} model=${model}\n`);
+  }
+  process.exit(0);
+}