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>

README.md

@@ -85,7 +85,9 @@ M0 of the runtime-profile work (additive, no behaviour change) introduces `profi
 
 Phase 1 of `/ultraplan-local` now resolves a profile in the order `--profile flag → brief.recommended_profile → default fallback` and reports `Profile: {name} (source: ...)` in the mode banner. M0 ships only `default.yaml`, which mirrors the current hardcoded Phase 5/9 agent set verbatim — so existing flows are unaffected.
 
-The remaining milestones layer on top: M1 wires profile recommendation into `/ultrabrief-local` Phase 4 (brief recommends a profile, user confirms or overrides). M2 ships additional built-in profiles (`quick`, `bugfix`, `feature`, `refactor`, `security-deep`, `research-heavy`) and replaces the hardcoded Phase 5 agent table with profile-driven selection. M3 adds user-extensible profiles in `.claude/ultraplan-profiles/` and `~/.claude/ultraplan-profiles/`.
+M1 (additive) adds the recommendation flow: a new `profile-recommender` sonnet agent ranks the available profiles against the finalized brief and writes `recommended_profile`/`profile_match`/`profile_rationale` to the brief frontmatter. `/ultrabrief-local` Phase 4 gains Step 4h: it short-circuits when only `default` exists, surfaces an `AskUserQuestion` confirmation when the top score reaches `RECOMMENDATION_THRESHOLD = 0.7`, and falls back to `default` with an explicit message otherwise. The brief itself stays universal — Step 4h does not branch on domain, only the downstream profile does.
+
+The remaining milestones layer on top: M2 ships additional built-in profiles (`quick`, `bugfix`, `feature`, `refactor`, `security-deep`, `research-heavy`) and replaces the hardcoded Phase 5 agent table with profile-driven selection. M3 adds user-extensible profiles in `.claude/ultraplan-profiles/` and `~/.claude/ultraplan-profiles/`.
 
 The whole design preserves a universal brief: `/ultrabrief-local` asks the same questions regardless of domain, and the profile is a *processing decision* layered on top of that universal data capture. No silent variant routing, no hidden magic — the active profile is always reported and overridable.