feat(ultraplan-local): v2.1.0 — dynamic quality-gated interview

Replace hardcoded Q1-Q8 in /ultrabrief-local with a section-driven
completeness loop (Phase 3) and a draft/review/revise loop with
brief-reviewer as stop-gate (Phase 4). Quality drives the interview,
not a question counter.

brief-reviewer now emits a machine-readable JSON block with per-dimension
scores (1-5) and detail arrays alongside the existing prose report;
planning-orchestrator continues to consume the prose verdict unchanged.

Phase 4 gate: all dimensions >= 4 AND research_plan = 5. On fail, a
targeted follow-up is generated from the weakest dimension's detail
field and the draft is re-reviewed. Max 3 review iterations bound cost;
exhaustion writes brief.md with brief_quality: partial and an explicit
Brief Quality section. Force-stop surfaces per-dimension findings before
the user chooses continue or partial.

Not breaking. /ultrabrief-local [--quick] <task> interface unchanged.
--quick now means compact start with escalation, not a max-N cap.

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

plugins/ultraplan-local/CHANGELOG.md

@@ -4,6 +4,61 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
+## [2.1.0] - 2026-04-18
+
+### Changed — Dynamic, quality-gated interview in `/ultrabrief-local`
+
+The Phase 3 interview is no longer a hardcoded Q1–Q8 list with a numeric
+cap (3–4 questions in `--quick`, 5–8 in default). It is now a
+**section-driven completeness loop**: the command maintains per-section
+state (Intent, Goal, Success Criteria, Research Plan, and five optional
+sections), picks the next question from the section with the weakest
+signal, and keeps probing until all four required sections meet an
+initial-signal gate. Quality drives the loop, not a counter.
+
+Phase 4 adds a **draft → brief-reviewer → revise** loop. The brief is
+drafted in memory, written to `brief.md.draft`, reviewed by the
+`brief-reviewer` agent as a stop-gate, and only renamed to `brief.md`
+after all five dimensions pass (`completeness/consistency/testability/
+scope_clarity ≥ 4` and `research_plan == 5`). If the gate fails, a
+targeted follow-up is generated from the weakest dimension's detail
+field and the draft is re-reviewed. The loop is capped at 3 review
+iterations to bound cost; exhaustion writes the brief with
+`brief_quality: partial` and an explicit `## Brief Quality` section.
+
+Force-stop path: when the user says "stop" during Phase 4, the current
+review findings are surfaced with per-dimension scores before asking
+whether to continue or accept a partial brief. No silent exits.
+
+Not breaking. The `/ultrabrief-local [--quick] <task>` interface is
+unchanged from the outside; only internals change. `--quick` now means
+"start compact, escalate if gates fail" rather than "max 4 questions".
+
+### Added
+
+- **JSON output from `brief-reviewer`** — the agent now emits a final
+  fenced `json` block with per-dimension `score` (1–5) and `detail`
+  arrays (`gaps`, `issues`, `weak_criteria`, `unclear_sections`,
+  `invalid_topics`) alongside the existing prose report. The JSON block
+  is mandatory; empty arrays and `score: 5` are required when a
+  dimension passes cleanly. `planning-orchestrator` continues to use
+  the prose verdict unchanged.
+- **`brief_quality` frontmatter field** on task briefs — `complete`
+  (default) when the Phase 4 gate passed, or `partial` when the
+  iteration cap was hit or the user force-stopped with known issues.
+  `planning-orchestrator` can inspect this to decide how heavily to
+  weight brief sections as assumptions.
+- **`review_iterations` and `brief_quality` in ultrabrief-stats** —
+  recorded per run for telemetry.
+
+### Changed
+
+- Hard rule added: `/ultrabrief-local` never writes `brief.md` while the
+  review gate is pending. The draft lives in `brief.md.draft` until the
+  loop terminates.
+- Hard rule added: no hard cap on Phase 3 questions; the brief-review
+  gate is the only loop bound (3-iteration cap) and is in Phase 4.
+
 ## [2.0.0] - 2026-04-18
 
 ### Breaking — Four-command pipeline with dedicated brief step