feat(ultraplan-local): M1 — profile recommendation flow in ultrabrief

Adds the profile recommendation step to /ultrabrief-local Phase 4. The
brief stays universal (same questions, same template); the new step is
purely a processing-decision layer that records which profile downstream
commands should apply.

What lands:
- agents/profile-recommender.md — new sonnet agent that scores available
  profiles against the finalized brief (keyword + NFR-signal matching,
  axis bumps, hallucination gate that forbids inventing profile names).
  Emits a fenced JSON block with ranked entries.
- templates/ultrabrief-template.md — frontmatter gains
  recommended_profile, profile_match, profile_rationale (default values
  applied when only `default` is available — true at M1).
- commands/ultrabrief-local.md — Phase 4 gains Step 4h with explicit
  branches: short-circuit when only `default` exists; AskUserQuestion
  confirmation when top score ≥ 0.7; explicit fallback message when below
  threshold; manual selection sub-question on user override. Persists the
  three frontmatter fields to brief.md after user confirmation. JSON
  parser failure falls back to `default` with `profile_match: fallback`
  rather than blocking — silent fallback is the worst outcome, but a
  *visible* fallback is acceptable.
- scripts/profile-loader.mjs — adds selectRecommendation(ranked, opts) +
  RECOMMENDATION_THRESHOLD=0.7 export. Single source of truth for the
  threshold logic so the command spec and the helper agree.
- scripts/profile-loader.test.mjs — 10 new tests for selectRecommendation
  (default-only, empty/malformed input, above/below threshold, custom
  threshold, max-by-score, missing fields). Total now 36/36.
- README.md / CLAUDE.md / marketplace landing — docs reflect M0 + M1
  shipped, M2 + M3 still pending.

In practice nothing changes for users at M1 because only `default` is
available — Step 4h takes the short-circuit path and writes
`profile_match: default-only`. M2 ships the additional profiles that
make the recommender meaningful.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

plugins/ultraplan-local/scripts/profile-loader.mjs

@@ -400,6 +400,98 @@ async function missingAgents(names, agentsDir) {
   return missing;
 }
 
+// =====================================================================
+// Recommendation helper
+// =====================================================================
+
+/**
+ * Recommendation threshold used by ultrabrief-local Step 4h. The
+ * profile-recommender agent's top-ranked profile must reach this score to
+ * be presented as a recommendation; below it, ultrabrief falls back to
+ * `default` with an explicit message.
+ */
+export const RECOMMENDATION_THRESHOLD = 0.7;
+
+/**
+ * Decide what to do with a `profile-recommender` agent's ranked output.
+ * Returns `{ profile, match, rationale, source }` where:
+ *   - `source` is `recommended` (top ≥ threshold), `fallback` (top < threshold
+ *     or empty input), or `default-only` (only `default` available).
+ *   - `profile` is the chosen profile name.
+ *   - `match` is one of `exact | partial | fallback | default-only`.
+ *   - `rationale` is a one-sentence explanation suitable for the brief
+ *     frontmatter.
+ *
+ * Rules:
+ *   - If `availableProfiles` only contains `default`, return `default-only`.
+ *   - If `ranked` is empty/malformed, fall back to `default` with a fallback
+ *     rationale.
+ *   - Otherwise pick the highest-scoring entry; recommend it only when
+ *     `score >= RECOMMENDATION_THRESHOLD`. Below threshold, recommend
+ *     `default` with `match: fallback` and the top entry's rationale.
+ */
+export function selectRecommendation(ranked, opts = {}) {
+  const threshold = opts.threshold ?? RECOMMENDATION_THRESHOLD;
+  const available = opts.availableProfiles ?? null;
+
+  if (Array.isArray(available) && available.length === 1 && available[0] === 'default') {
+    return {
+      profile: 'default',
+      match: 'default-only',
+      rationale: 'Only the default profile is available; recommendation skipped.',
+      source: 'default-only',
+    };
+  }
+
+  if (!Array.isArray(ranked) || ranked.length === 0) {
+    return {
+      profile: 'default',
+      match: 'fallback',
+      rationale: 'profile-recommender returned no ranked profiles; using default.',
+      source: 'fallback',
+    };
+  }
+
+  // Find highest-scoring entry. Treat missing/non-numeric scores as 0.
+  let top = null;
+  for (const entry of ranked) {
+    if (!entry || typeof entry.name !== 'string') continue;
+    const score = typeof entry.score === 'number' ? entry.score : 0;
+    if (top === null || score > (typeof top.score === 'number' ? top.score : 0)) {
+      top = { ...entry, score };
+    }
+  }
+
+  if (top === null) {
+    return {
+      profile: 'default',
+      match: 'fallback',
+      rationale: 'profile-recommender output had no usable entries; using default.',
+      source: 'fallback',
+    };
+  }
+
+  if (top.score >= threshold) {
+    return {
+      profile: top.name,
+      match: typeof top.match_quality === 'string' ? top.match_quality : 'partial',
+      rationale: typeof top.rationale === 'string' && top.rationale.trim() !== ''
+        ? top.rationale
+        : `Top-ranked profile (score ${top.score}).`,
+      source: 'recommended',
+    };
+  }
+
+  return {
+    profile: 'default',
+    match: 'fallback',
+    rationale: typeof top.rationale === 'string' && top.rationale.trim() !== ''
+      ? `Top score ${top.score} below ${threshold}; ${top.rationale}`
+      : `Top score ${top.score} below recommendation threshold ${threshold}.`,
+    source: 'fallback',
+  };
+}
+
 // =====================================================================
 // CLI
 // =====================================================================