matrix: cross-role playbook gate — closes real_001 bleed (OPEN #1)

real_001 surfaced same-client+city queries bleeding across roles:
Q#2 (Forklift Operator @ Beacon Freight Detroit) recorded e-6193
in the playbook corpus. Q#5 (Pickers same client+city) and Q#10
(CNC Operator same client+city) embedded within 0.13-0.18 cosine of
Q#2's query — well inside the 0.20 inject threshold — so e-6193
injected on both, demoting the cold-pass-correct workers.

Root cause: the inject distance threshold isn't tight enough on
the same-client+city cluster. Cosine collapses queries that share
city + client + count-token + time-token regardless of role. The
existing judge gate is per-injection at record time and doesn't
fire at retrieve time.

Fix: structural role gate in front of both Shape A boost and
Shape B inject. PlaybookEntry gains Role; SearchRequest gains
QueryRole. When both are non-empty and differ under roleEqual's
case+plural normalization, the entry is rejected before BoostFactor
or judge-gate logic runs.

Backward-compat: empty role on either side disables the gate —
preserves behavior for the lift suite's free-form multi-constraint
queries that have no clean single role. Caller-supplied (not
inferred), so existing recordings unaffected.

Wire-through:
- internal/matrix/playbook.go: Role field, NewPlaybookEntryWithRole,
  roleEqual helper with plural+case normalization
- internal/matrix/retrieve.go: QueryRole on SearchRequest, threaded
  to both ApplyPlaybookBoost + InjectPlaybookMisses
- cmd/matrixd/main.go: role on POST /matrix/playbooks/record + bulk
- scripts/playbook_lift/main.go: extractRoleFromNeed regex pulls
  role from "Need N {role}{s} in" queries (the fill_events shape);
  free-form queries fall back to empty (gate disabled)

Tests (5 new):
- TestInjectPlaybookMisses_RoleGateRejectsCrossRole: exact Q#10
  scenario (distance 0.135, recorded "Forklift Operator", query
  "CNC Operator") — locks the bleed at unit level
- TestInjectPlaybookMisses_RoleGateAllowsSameRole: Forklift Operator
  recording fires on Forklift Operators query (plural normalization)
- TestInjectPlaybookMisses_RoleGateBackwardCompat: empty Role on
  either side = gate disabled, preserves current behavior
- TestApplyPlaybookBoost_RoleGateRejectsCrossRole: Shape A defense
  in depth — boost doesn't fire on cross-role even when answer is
  in cold top-K
- TestRoleEqual_PluralAndCase: case + -s + -es plural normalization

Verification (real_002, same query set as real_001):
- Q#5 Pickers @ Beacon Freight: e-6193 → e-8499 (no bleed)
- Q#10 CNC Operator @ Beacon Freight: e-6193 → w-2404 (no bleed)
- Discoveries + lifts unchanged at 2 each (same-role lift still fires)
- Mean Δdist tightens from -0.127 to -0.040 (boosts no longer
  pulling distances through the floor on cross-role mismatches)

Findings: reports/reality-tests/real_002_findings.md.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

cmd/matrixd/main.go

@@ -118,8 +118,13 @@ func (h *handlers) handleRelevance(w http.ResponseWriter, r *http.Request) {
 
 // playbookRecordRequest is the POST /matrix/playbooks/record body.
 // Corpus is optional; defaults to matrix.DefaultPlaybookCorpus.
+// Role is optional; when set, gates Shape A boost + Shape B inject
+// at retrieve time so this entry only fires for queries with the
+// same role (real_001 cross-role bleed fix). Empty Role = current
+// behavior (no gate).
 type playbookRecordRequest struct {
 	QueryText    string   `json:"query_text"`
+	Role         string   `json:"role,omitempty"`
 	AnswerID     string   `json:"answer_id"`
 	AnswerCorpus string   `json:"answer_corpus"`
 	Score        float64  `json:"score"`
@@ -132,7 +137,7 @@ func (h *handlers) handlePlaybookRecord(w http.ResponseWriter, r *http.Request)
 	if !decodeJSON(w, r, &req) {
 		return
 	}
-	entry := matrix.NewPlaybookEntry(req.QueryText, req.AnswerID, req.AnswerCorpus, req.Score, req.Tags)
+	entry := matrix.NewPlaybookEntryWithRole(req.QueryText, req.Role, req.AnswerID, req.AnswerCorpus, req.Score, req.Tags)
 	if err := entry.Validate(); err != nil {
 		http.Error(w, err.Error(), http.StatusBadRequest)
 		return
@@ -195,7 +200,7 @@ func (h *handlers) handlePlaybookBulk(w http.ResponseWriter, r *http.Request) {
 		if corpus == "" {
 			corpus = req.Corpus
 		}
-		entry := matrix.NewPlaybookEntry(item.QueryText, item.AnswerID, item.AnswerCorpus, item.Score, item.Tags)
+		entry := matrix.NewPlaybookEntryWithRole(item.QueryText, item.Role, item.AnswerID, item.AnswerCorpus, item.Score, item.Tags)
 		if err := entry.Validate(); err != nil {
 			out.Results[i] = playbookBulkItemResult{Index: i, Error: err.Error()}
 			out.Failed++