feat(voyage): S6 — v5.5 brief framing enforcement (brief_version 2.2)

Implements the CLAUDE.md cross-cutting invariant "brief framing must match
operator intent" as a controlled brief_version 2.1->2.2 bump (operator option A1).
Three defense layers, version-gated at >=2.2 so existing 2.0/2.1 briefs stay
valid (forward + backward compatible), mirroring the phase_signals >=2.1 gate:

- L1 framing: enum field (preserve|refine|replace|new-direction). Enum-checked
  on any version when present (BRIEF_INVALID_FRAMING); missing at >=2.2 ->
  BRIEF_MISSING_FRAMING. /trekbrief Phase 2.5 collects it BEFORE any brief prose
  (non-skippable, even in --quick).
- L2 memory alignment: new brief-reviewer dimension 6 comparing brief Intent/Goal
  + framing against operator memory for explicit contradictions; degrades to
  score 5 (N/A) when no memory context is supplied. Wired into Phase 4e gate
  (memory_alignment.score >= 4).
- L3 obligatory ## TL;DR (<=5 content lines) at >=2.2; soft cap ->
  BRIEF_TLDR_TOO_LONG warning.

trekreview briefs are exempt from the framing/TL;DR gate. Handover 1 PUBLIC
CONTRACT doc, README "What's new", and the CLAUDE.md invariant + agents table
(brief-reviewer 5->6 dimensions) updated to 2.2 (schema axis only; plugin
version badge + CHANGELOG remain S10).

Iron Law followed: validator tests red->green first. Tests 586 -> 606
(+20, 604 pass / 2 skip). claude plugin validate passes (pre-existing
CLAUDE.md root-context warning unchanged).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LqBYc8Ltrk7LipyJmGxXiB

tests/validators/brief-validator.test.mjs

@@ -250,3 +250,111 @@ test('validateBrief — v5.1.1: UNQUOTED brief_version 2.1 WITH phase_signals is
   assert.equal(r.valid, true, JSON.stringify(r.errors));
   assert.ok(!r.errors.find(e => e.code === 'BRIEF_V51_MISSING_SIGNALS'));
 });
+
+// --- v5.5 — framing enforcement + obligatory TL;DR (gated at brief_version ≥ 2.2) ---
+// Operator decision (S6, option A1): framing + TL;DR are hard BLOCKERs for briefs
+// declaring brief_version ≥ 2.2; existing 2.0/2.1 briefs stay valid (forward-compat,
+// mirroring the phase_signals ≥ 2.1 precedent). The framing ENUM check fires on any
+// version when the field is present but malformed.
+
+const GOOD_BRIEF_22 = `---
+type: trekbrief
+brief_version: "2.2"
+created: 2026-06-18
+task: "Add JWT auth to API"
+slug: jwt-auth
+project_dir: .claude/projects/2026-06-18-jwt-auth/
+research_topics: 0
+research_status: complete
+auto_research: false
+interview_turns: 5
+source: interview
+framing: new-direction
+phase_signals_partial: true
+---
+
+# Task: JWT auth
+
+## TL;DR
+
+Net-new JWT auth; no prior brief to anchor against.
+
+## Intent
+
+Why this matters.
+
+## Goal
+
+What success looks like.
+
+## Success Criteria
+
+- All tests pass.
+`;
+
+test('validateBrief — v5.5 well-formed 2.2 brief (framing + TL;DR) accepted', () => {
+  const r = validateBriefContent(GOOD_BRIEF_22, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+});
+
+test('validateBrief — v5.5 framing enum: invalid value rejected on any version', () => {
+  const t = GOOD_BRIEF.replace('source: interview\n', 'source: interview\nframing: sideways\n');
+  const r = validateBriefContent(t, { strict: true });
+  assert.equal(r.valid, false);
+  assert.ok(r.errors.find(e => e.code === 'BRIEF_INVALID_FRAMING'));
+});
+
+test('validateBrief — v5.5 framing enum: all four canonical values accepted', () => {
+  for (const v of ['preserve', 'refine', 'replace', 'new-direction']) {
+    const t = GOOD_BRIEF_22.replace('framing: new-direction', `framing: ${v}`);
+    const r = validateBriefContent(t, { strict: true });
+    assert.equal(r.valid, true, `framing=${v}: ${JSON.stringify(r.errors)}`);
+  }
+});
+
+test('validateBrief — v5.5 brief_version 2.2 missing framing rejected (BRIEF_MISSING_FRAMING)', () => {
+  const t = GOOD_BRIEF_22.replace('framing: new-direction\n', '');
+  const r = validateBriefContent(t, { strict: true });
+  assert.equal(r.valid, false);
+  assert.ok(r.errors.find(e => e.code === 'BRIEF_MISSING_FRAMING'));
+});
+
+test('validateBrief — v5.5 brief_version 2.2 missing ## TL;DR rejected (strict)', () => {
+  const t = GOOD_BRIEF_22.replace(/## TL;DR\n\n[^\n]*\n\n/, '');
+  const r = validateBriefContent(t, { strict: true });
+  assert.equal(r.valid, false);
+  assert.ok(r.errors.find(e => e.code === 'BRIEF_MISSING_SECTION' && /TL;DR/.test(e.message)));
+});
+
+test('validateBrief — v5.5 brief_version 2.2 missing ## TL;DR demoted to warning (soft)', () => {
+  const t = GOOD_BRIEF_22.replace(/## TL;DR\n\n[^\n]*\n\n/, '');
+  const r = validateBriefContent(t, { strict: false });
+  assert.ok(r.warnings.find(w => w.code === 'BRIEF_MISSING_SECTION' && /TL;DR/.test(w.message)));
+});
+
+test('validateBrief — v5.5 TL;DR exceeding 5 lines emits BRIEF_TLDR_TOO_LONG warning', () => {
+  const longTldr = ['l1', 'l2', 'l3', 'l4', 'l5', 'l6'].join('\n');
+  const t = GOOD_BRIEF_22.replace('Net-new JWT auth; no prior brief to anchor against.', longTldr);
+  const r = validateBriefContent(t, { strict: true });
+  assert.ok(
+    r.warnings.find(w => w.code === 'BRIEF_TLDR_TOO_LONG'),
+    `expected TL;DR-too-long warning; warnings=${JSON.stringify(r.warnings)}`,
+  );
+});
+
+test('validateBrief — v5.5 backward-compat: 2.1 brief without framing/TL;DR stays valid', () => {
+  const t = GOOD_BRIEF
+    .replace('brief_version: "2.0"', 'brief_version: "2.1"')
+    .replace('source: interview\n', 'source: interview\nphase_signals_partial: true\n');
+  const r = validateBriefContent(t, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+  assert.ok(!r.errors.find(e => e.code === 'BRIEF_MISSING_FRAMING'));
+  assert.ok(!r.errors.find(e => e.code === 'BRIEF_MISSING_SECTION' && /TL;DR/.test(e.message)));
+});
+
+test('validateBrief — v5.5 trekreview brief not subject to framing/TL;DR gate', () => {
+  const r = validateBriefContent(REVIEW_AS_BRIEF, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+  assert.ok(!r.errors.find(e => e.code === 'BRIEF_MISSING_FRAMING'));
+  assert.ok(!r.errors.find(e => e.code === 'BRIEF_MISSING_SECTION' && /TL;DR/.test(e.message)));
+});