feat(nomos): session-review improvements (P0/P1/P2 from 2026-07-20 audit)

Classifier now unwraps pct exec / qm guest exec / bash -c / sh -c / sudo
and env-var assignments before classification, so read-only inspection
wrapped in pct exec no longer escalates to config_mutation. curl GET
(default method, no -d/-F/-T/-o/>) is read-only. Eliminates the three
duplicate rclone sessions (a51e2086, 8acea2e3, cb8c8a4a) that bounced
off the classifier for the same goal.

New classify_command MCP tool: command-scoped preflight that returns the
exact risk class run would assign. Documented in SOUL.md with guidance
to pre-classify before run when the verdict is uncertain.

set_goal surfaces prior partial/failed sessions from the last 24h so the
agent picks up the thread instead of rediscovering it.

completeTask auto-closes in-flight plan steps (pending/running -> done
on success, skipped on partial/failure), so one-step plans no longer
need the per-step running->done dance right before completion.

Migration 021 adds blocker + closed_at to agent_sessions. completeTask
sets closed_at once and derives a structured blocker reason
(approval_timeout, user_abandoned, classifier_overreach, model_refusal,
tool_error, ...) from the last assistant message.

/sessions list now carries message_count, tool_call_count,
duration_seconds (server-side aggregates — no more N+1 transcript
fetches to audit a fleet). GET /sessions/{id} returns both metadata
and messages. New query params filter + paginate: outcome, status,
entity_id, blocker, since (RFC3339 or Go duration), cursor, limit.

Titles now prefer the goal when set; sessions without a goal fall back
to the first assistant text.

New GET /sessions/{id}/tool_calls flat view for audit scripts.

Plan: plans/2026-07-20-session-review-ten-sessions.md. VERSION 0.7.12 -> 0.7.13.

cmd/nomos/store.go

@@ -86,18 +86,39 @@ func (s *store) close() {
 // session is a chat session elevated to a task: goal-structured work with a
 // lifecycle status and an outcome (see migration 018 / the task-board plan).
 // Outcome/Summary/EntityID are empty until set, hence omitempty.
+//
+// P1.5 (2026-07-20): Blocker and ClosedAt track WHY a session ended
+// partial/failed and WHEN it actually closed. ClosedAt is distinct from
+// LastActiveAt — the latter is touched on any access (including a UI
+// transcript view), the former is set ONCE at completion. Without it,
+// "duration" computed as last_active - created lies for reopened sessions
+// (a51e2086 reported 4-day duration because the operator reopened it).
+// Blocker is a short structured reason: approval_timeout,
+// classifier_overreach, user_abandoned, tool_error, etc. See
+// plans/2026-07-20-session-review-ten-sessions.md P1.5.
 type session struct {
-	ID               string    `json:"id"`
-	Title            string    `json:"title"`
-	Actor            string    `json:"actor"`
-	Goal             string    `json:"goal"`
-	Status           string    `json:"status"`
-	Outcome          string    `json:"outcome,omitempty"`
-	Summary          string    `json:"summary,omitempty"`
-	EntityID         string    `json:"entity_id,omitempty"`
-	PendingApprovals int       `json:"pending_approvals"`
-	CreatedAt        time.Time `json:"created_at"`
-	LastActiveAt     time.Time `json:"last_active_at"`
+	ID               string     `json:"id"`
+	Title            string     `json:"title"`
+	Actor            string     `json:"actor"`
+	Goal             string     `json:"goal"`
+	Status           string     `json:"status"`
+	Outcome          string     `json:"outcome,omitempty"`
+	Summary          string     `json:"summary,omitempty"`
+	EntityID         string     `json:"entity_id,omitempty"`
+	PendingApprovals int        `json:"pending_approvals"`
+	Blocker          string     `json:"blocker,omitempty"`
+	CreatedAt        time.Time  `json:"created_at"`
+	LastActiveAt     time.Time  `json:"last_active_at"`
+	ClosedAt         *time.Time `json:"closed_at,omitempty"`
+	// P2.6 (2026-07-20): server-side aggregates so /sessions can answer
+	// "how big was this task?" without N+1 transcript fetches. The audit
+	// had to pull every session's full message tree to count tool calls —
+	// ~600 KB of JSON for 10 sessions. With these, the list view is a
+	// single round trip. omitempty so getSession for a brand-new session
+	// with zero activity doesn't emit zeros.
+	MessageCount    int `json:"message_count,omitempty"`
+	ToolCallCount   int `json:"tool_call_count,omitempty"`
+	DurationSeconds int `json:"duration_seconds,omitempty"`
 }
 
 type message struct {
@@ -315,14 +336,98 @@ func (s *store) touchSession(ctx context.Context, id string) {
 }
 
 func (s *store) listSessions(ctx context.Context) ([]session, error) {
+	return s.listSessionsFiltered(ctx, listFilter{Limit: 50})
+}
+
+// listFilter carries the optional WHERE/ORDER clauses added by P2.8
+// (filtering & pagination). All fields optional; empty values are no-ops.
+// The handler in main.go parses query params into this struct so the SQL
+// builder here is the single source of truth for what filters exist.
+type listFilter struct {
+	Outcome  string // exact match on outcome (success/partial/failure)
+	Status   string // exact match on status (active/done/failed/executing)
+	EntityID string // exact match on entity_id (UUID)
+	Blocker  string // exact match on blocker reason
+	Since    string // last_active_at >= this; RFC3339 timestamp OR Go duration (e.g. "24h")
+	Cursor   string // last_active_at < cursor (RFC3339) — page back in time
+	Limit    int    // default 50, clamped by the handler
+}
+
+func (s *store) listSessionsFiltered(ctx context.Context, f listFilter) ([]session, error) {
 	if s == nil {
 		return nil, nil
 	}
-	rows, err := s.pool.Query(ctx,
-		`SELECT s.id, s.title, s.actor, s.goal, s.status, COALESCE(s.outcome, ''), s.summary,
-		        COALESCE(s.entity_id::text, ''),
-		        COALESCE(pa.cnt, 0),
-		        s.created_at, s.last_active_at
+	if f.Limit <= 0 {
+		f.Limit = 50
+	}
+	// Build the WHERE clause dynamically. We use a single args slice with
+	// $N placeholders to keep pgx happy; the index increments per clause.
+	var (
+		where []string
+		args  []any
+		n     = 1
+	)
+	if f.Outcome != "" {
+		where = append(where, fmt.Sprintf("COALESCE(s.outcome, '') = $%d", n))
+		args = append(args, f.Outcome)
+		n++
+	}
+	if f.Status != "" {
+		where = append(where, fmt.Sprintf("s.status = $%d", n))
+		args = append(args, f.Status)
+		n++
+	}
+	if f.EntityID != "" {
+		// Accept UUID or string; cast gracefully if invalid.
+		if _, err := uuid.Parse(f.EntityID); err == nil {
+			where = append(where, fmt.Sprintf("s.entity_id = $%d::uuid", n))
+			args = append(args, f.EntityID)
+			n++
+		}
+	}
+	if f.Blocker != "" {
+		where = append(where, fmt.Sprintf("COALESCE(s.blocker, '') = $%d", n))
+		args = append(args, f.Blocker)
+		n++
+	}
+	if f.Since != "" {
+		// Accept RFC3339 timestamp OR a Go-style duration like "24h", "7d".
+		// Try timestamp first, fall back to duration relative to now.
+		if t, err := time.Parse(time.RFC3339, f.Since); err == nil {
+			where = append(where, fmt.Sprintf("s.last_active_at >= $%d", n))
+			args = append(args, t)
+			n++
+		} else if d, err := time.ParseDuration(f.Since); err == nil {
+			where = append(where, fmt.Sprintf("s.last_active_at >= now() - ($%d * interval '1 second')", n))
+			args = append(args, d.Seconds())
+			n++
+		}
+		// Unknown format: silently drop the filter — better than erroring
+		// out and breaking the whole list. Caller can validate if needed.
+	}
+	if f.Cursor != "" {
+		if t, err := time.Parse(time.RFC3339, f.Cursor); err == nil {
+			where = append(where, fmt.Sprintf("s.last_active_at < $%d", n))
+			args = append(args, t)
+			n++
+		}
+	}
+	whereClause := ""
+	if len(where) > 0 {
+		whereClause = "WHERE " + strings.Join(where, " AND ")
+	}
+	args = append(args, f.Limit)
+	limitArg := fmt.Sprintf("$%d", n)
+
+	query := fmt.Sprintf(`
+		SELECT s.id, s.title, s.actor, s.goal, s.status, COALESCE(s.outcome, ''), s.summary,
+		       COALESCE(s.entity_id::text, ''),
+		       COALESCE(pa.cnt, 0),
+		       COALESCE(s.blocker, ''),
+		       s.created_at, s.last_active_at, s.closed_at,
+		       COALESCE(msg.cnt, 0),
+		       COALESCE(act.cnt, 0),
+		       COALESCE(EXTRACT(EPOCH FROM (COALESCE(s.closed_at, s.last_active_at) - s.created_at))::bigint, 0)
 		 FROM agent_sessions s
 		 LEFT JOIN (
 		   SELECT l.session_id, COUNT(*) AS cnt
@@ -331,7 +436,22 @@ func (s *store) listSessions(ctx context.Context) ([]session, error) {
 		   WHERE e.status = 'pending_approval'
 		   GROUP BY l.session_id
 		 ) pa ON pa.session_id = s.id
-		 ORDER BY s.last_active_at DESC LIMIT 50`)
+		 LEFT JOIN (
+		   SELECT session_id, COUNT(*) AS cnt
+		   FROM agent_messages
+		   GROUP BY session_id
+		 ) msg ON msg.session_id = s.id
+		 LEFT JOIN (
+		   SELECT session_id::uuid AS sid, COUNT(*) AS cnt
+		   FROM agent_activity
+		   WHERE session_id IS NOT NULL AND session_id <> ''
+		   GROUP BY session_id
+		 ) act ON act.sid = s.id
+		 %s
+		 ORDER BY s.last_active_at DESC
+		 LIMIT %s`, whereClause, limitArg)
+
+	rows, err := s.pool.Query(ctx, query, args...)
 	if err != nil {
 		return nil, err
 	}
@@ -342,7 +462,8 @@ func (s *store) listSessions(ctx context.Context) ([]session, error) {
 		var sess session
 		if err := rows.Scan(&sess.ID, &sess.Title, &sess.Actor, &sess.Goal, &sess.Status,
 			&sess.Outcome, &sess.Summary, &sess.EntityID, &sess.PendingApprovals,
-			&sess.CreatedAt, &sess.LastActiveAt); err != nil {
+			&sess.Blocker, &sess.CreatedAt, &sess.LastActiveAt, &sess.ClosedAt,
+			&sess.MessageCount, &sess.ToolCallCount, &sess.DurationSeconds); err != nil {
 			return nil, err
 		}
 		out = append(out, sess)
@@ -356,18 +477,102 @@ func (s *store) getSession(ctx context.Context, id string) (*session, error) {
 	}
 	var sess session
 	err := s.pool.QueryRow(ctx,
-		`SELECT id, title, actor, goal, status, COALESCE(outcome, ''), summary,
-		        COALESCE(entity_id::text, ''), 0, created_at, last_active_at
-		 FROM agent_sessions WHERE id = $1`, id).
+		`SELECT s.id, s.title, s.actor, s.goal, s.status, COALESCE(s.outcome, ''), s.summary,
+		        COALESCE(s.entity_id::text, ''), 0, COALESCE(s.blocker, ''),
+		        s.created_at, s.last_active_at, s.closed_at,
+		        COALESCE(msg.cnt, 0),
+		        COALESCE(act.cnt, 0),
+		        COALESCE(EXTRACT(EPOCH FROM (COALESCE(s.closed_at, s.last_active_at) - s.created_at))::bigint, 0)
+		 FROM agent_sessions s
+		 LEFT JOIN (
+		   SELECT session_id, COUNT(*) AS cnt
+		   FROM agent_messages
+		   WHERE session_id = $1::uuid
+		   GROUP BY session_id
+		 ) msg ON msg.session_id = s.id
+		 LEFT JOIN (
+		   SELECT session_id::uuid AS sid, COUNT(*) AS cnt
+		   FROM agent_activity
+		   WHERE session_id IS NOT NULL AND session_id <> ''
+		     AND session_id::uuid = $1::uuid
+		   GROUP BY session_id
+		 ) act ON act.sid = s.id
+		 WHERE s.id = $1`, id).
 		Scan(&sess.ID, &sess.Title, &sess.Actor, &sess.Goal, &sess.Status,
 			&sess.Outcome, &sess.Summary, &sess.EntityID, &sess.PendingApprovals,
-			&sess.CreatedAt, &sess.LastActiveAt)
+			&sess.Blocker, &sess.CreatedAt, &sess.LastActiveAt, &sess.ClosedAt,
+			&sess.MessageCount, &sess.ToolCallCount, &sess.DurationSeconds)
 	if err != nil {
 		return nil, err
 	}
 	return &sess, nil
 }
 
+// recentPartialSessions returns recent sessions (within `since`) whose outcome
+// is partial or failed, excluding the current session. Used by the set_goal
+// handler to surface prior unfinished work on the same problem — three
+// duplicate rclone sessions (a51e2086, 8acea2e3, cb8c8a4a) all bounced off
+// the classifier because each new session started from scratch. Surfacing the
+// prior session's goal + summary at set_goal time lets the agent pick up the
+// thread instead of rediscovering it. See
+// plans/2026-07-20-session-review-ten-sessions.md P1.3.
+func (s *store) recentPartialSessions(ctx context.Context, excludeSessionID string, since time.Duration) ([]session, error) {
+	if s == nil {
+		return nil, nil
+	}
+	rows, err := s.pool.Query(ctx,
+		`SELECT s.id, s.title, s.actor, s.goal, s.status, COALESCE(s.outcome, ''), s.summary,
+		        COALESCE(s.entity_id::text, ''),
+		        COALESCE(pa.cnt, 0),
+		        COALESCE(s.blocker, ''),
+		        s.created_at, s.last_active_at, s.closed_at,
+		        COALESCE(msg.cnt, 0),
+		        COALESCE(act.cnt, 0),
+		        COALESCE(EXTRACT(EPOCH FROM (COALESCE(s.closed_at, s.last_active_at) - s.created_at))::bigint, 0)
+		 FROM agent_sessions s
+		 LEFT JOIN (
+		   SELECT l.session_id, COUNT(*) AS cnt
+		   FROM nomos_plan_executions l
+		   JOIN executions e ON e.entity_id = l.execution_id
+		   WHERE e.status = 'pending_approval'
+		   GROUP BY l.session_id
+		 ) pa ON pa.session_id = s.id
+		 LEFT JOIN (
+		   SELECT session_id, COUNT(*) AS cnt
+		   FROM agent_messages
+		   GROUP BY session_id
+		 ) msg ON msg.session_id = s.id
+		 LEFT JOIN (
+		   SELECT session_id::uuid AS sid, COUNT(*) AS cnt
+		   FROM agent_activity
+		   WHERE session_id IS NOT NULL AND session_id <> ''
+		   GROUP BY session_id
+		 ) act ON act.sid = s.id
+		 WHERE s.id <> $1
+		   AND s.last_active_at >= now() - ($2 * interval '1 second')
+		   AND COALESCE(s.outcome, '') IN ('partial', 'failed')
+		 ORDER BY s.last_active_at DESC
+		 LIMIT 10`,
+		excludeSessionID, since.Seconds())
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var out []session
+	for rows.Next() {
+		var sess session
+		if err := rows.Scan(&sess.ID, &sess.Title, &sess.Actor, &sess.Goal, &sess.Status,
+			&sess.Outcome, &sess.Summary, &sess.EntityID, &sess.PendingApprovals,
+			&sess.Blocker, &sess.CreatedAt, &sess.LastActiveAt, &sess.ClosedAt,
+			&sess.MessageCount, &sess.ToolCallCount, &sess.DurationSeconds); err != nil {
+			return nil, err
+		}
+		out = append(out, sess)
+	}
+	return out, rows.Err()
+}
+
 // getMessages returns a session's ENTIRE message history, unbounded — used
 // for the UI's own transcript view (GET /sessions/{id}), where the operator
 // should be able to see everything a task has done regardless of how long
@@ -397,6 +602,77 @@ func (s *store) getMessages(ctx context.Context, sessionID string) ([]message, e
 	return out, rows.Err()
 }
 
+// SessionToolCall is the flat view of one tool call as exposed by
+// GET /sessions/{id}/tool_calls. Mirrors the persisted tool_call shape but
+// drops the message-shell wrapping. Args/Result are kept as RawMessage so
+// the caller can decide how to render them (the audit case wanted raw
+// text sizes, but other callers may want full JSON).
+type SessionToolCall struct {
+	ID        string          `json:"id"`
+	Name      string          `json:"name"`
+	Args      json.RawMessage `json:"args,omitempty"`
+	Result    json.RawMessage `json:"result,omitempty"`
+	Error     string          `json:"error,omitempty"`
+	Type      string          `json:"type,omitempty"` // "tool_use" or "tool_result"
+	MessageID string          `json:"message_id"`
+	Role      string          `json:"role"`
+	Seq       int             `json:"seq"` // 1-indexed position within the session (across all messages)
+	CreatedAt time.Time       `json:"created_at"`
+}
+
+// getSessionToolCalls walks a session's messages and returns a flat list of
+// tool calls in chronological order, without the two-level message nesting.
+// The audit at plans/2026-07-20-session-review-ten-sessions.md P2.10 had to
+// write Python to walk messages[].content.tool_calls[]; this method makes
+// it a single SQL + Go walk on the server. Each tool_use/tool_result pair
+// is emitted as two rows (same id, different Type), preserving the
+// persisted shape — clients that want the merged shape can group by ID.
+func (s *store) getSessionToolCalls(ctx context.Context, sessionID string) ([]SessionToolCall, error) {
+	if s == nil {
+		return nil, nil
+	}
+	msgs, err := s.getMessages(ctx, sessionID)
+	if err != nil {
+		return nil, err
+	}
+	var out []SessionToolCall
+	seq := 0
+	for _, m := range msgs {
+		var payload struct {
+			ToolCalls []struct {
+				ID     string          `json:"id"`
+				Type   string          `json:"type"`
+				Name   string          `json:"name"`
+				Args   json.RawMessage `json:"args"`
+				Result json.RawMessage `json:"result"`
+				Error  string          `json:"error"`
+			} `json:"tool_calls"`
+		}
+		if err := json.Unmarshal(m.Content, &payload); err != nil {
+			continue
+		}
+		for _, tc := range payload.ToolCalls {
+			if tc.ID == "" {
+				continue
+			}
+			seq++
+			out = append(out, SessionToolCall{
+				ID:        tc.ID,
+				Name:      tc.Name,
+				Args:      tc.Args,
+				Result:    tc.Result,
+				Error:     tc.Error,
+				Type:      tc.Type,
+				MessageID: m.ID,
+				Role:      m.Role,
+				Seq:       seq,
+				CreatedAt: m.CreatedAt,
+			})
+		}
+	}
+	return out, nil
+}
+
 // getRecentMessages returns the most recent `limit` messages for sessionID,
 // in chronological order, plus whether older messages exist beyond that
 // window. Used specifically for LLM replay (chatWith): without a bound,
@@ -528,7 +804,7 @@ func (s *store) setGoal(ctx context.Context, sessionID, goal string) error {
 		`UPDATE session_plan_steps SET status = 'replaced', finished_at = COALESCE(finished_at, now()) WHERE session_id = $1 AND status <> 'replaced'`,
 		sessionID)
 	if _, err := s.pool.Exec(ctx,
-		`UPDATE agent_sessions SET goal = $2, status = 'executing', last_active_at = now() WHERE id = $1`,
+		`UPDATE agent_sessions SET goal = $2, status = 'executing', title = $2, last_active_at = now() WHERE id = $1`,
 		sessionID, goal); err != nil {
 		return err
 	}
@@ -809,6 +1085,27 @@ func (s *store) completeTask(ctx context.Context, sessionID, outcome, summary st
 	s.pool.Exec(ctx, `UPDATE nomos_plan_executions SET continued_at = now()
 		WHERE session_id = $1 AND continued_at IS NULL`, sessionID)
 
+	// P1.4 (2026-07-20): auto-close any in-flight plan steps so the agent
+	// doesn't need an update_plan_step(running)→update_plan_step(done)
+	// dance for each step right before completion. Session 8c76bb3a
+	// (greeting + title-sync test) burned 4 update_plan_step calls for a
+	// one-step plan. completeTask is the authoritative terminal — any
+	// step still in pending/running when the task ends is closed (as
+	// "done" for success, "skipped" for partial/failure) so the UI's plan
+	// view doesn't show orphaned running steps on a completed task.
+	// Replaced/cancelled/blocked steps are left alone.
+	closeStatus := "done"
+	if outcome != "success" {
+		closeStatus = "skipped"
+	}
+	if _, err := s.pool.Exec(ctx, `
+		UPDATE session_plan_steps
+		SET status = $3, finished_at = COALESCE(finished_at, now())
+		WHERE session_id = $1 AND status IN ('pending', 'running')`,
+		sessionID, "", closeStatus); err != nil {
+		slog.Warn("nomos: completeTask failed to auto-close in-flight steps", "session", sessionID, "error", err)
+	}
+
 	// Clean up assent and destructive window keys from autonomy_settings.
 	s.pool.Exec(ctx, `DELETE FROM autonomy_settings
 		WHERE key LIKE '%:' || $1`, sessionID)
@@ -817,9 +1114,22 @@ func (s *store) completeTask(ctx context.Context, sessionID, outcome, summary st
 	if outcome == "failure" {
 		status = "failed"
 	}
+	// P1.5 (2026-07-20): derive a structured blocker reason when the
+	// outcome is partial/failed, so trend analysis can answer "why are
+	// sessions failing?" without parsing free-text summaries. Three
+	// duplicate rclone sessions (a51e2086, 8acea2e3, cb8c8a4a) all
+	// bounced off the classifier; without a blocker field, the *why* was
+	// buried in the last assistant message. The signatures matched here
+	// are the recurring ones from the 2026-07-20 session audit. Empty for
+	// success — that's not a blocker.
+	blocker := ""
+	if outcome != "success" {
+		blocker = deriveBlocker(ctx, s, sessionID, summary)
+	}
 	if _, err := s.pool.Exec(ctx, `
-		UPDATE agent_sessions SET status = $2, outcome = $3, summary = $4, last_active_at = now()
-		WHERE id = $1`, sessionID, status, outcome, summary); err != nil {
+		UPDATE agent_sessions SET status = $2, outcome = $3, summary = $4,
+		                          blocker = $5, closed_at = now(), last_active_at = now()
+		WHERE id = $1`, sessionID, status, outcome, summary, blocker); err != nil {
 		return err
 	}
 	var entID uuid.UUID
@@ -837,10 +1147,58 @@ func (s *store) completeTask(ctx context.Context, sessionID, outcome, summary st
 	}
 	_ = observability.Event(ctx, sqlcgen.New(s.pool), "task.status", entPtr, severity, "nomos", sessionID,
 		map[string]any{"status": status, "outcome": outcome, "summary": summary,
-			"cancelled_executions": cancelledCount})
+			"cancelled_executions": cancelledCount, "blocker": blocker})
 	return nil
 }
 
+// blockerPatterns maps a substring (case-insensitive) to a structured blocker
+// reason. Order matters — earlier patterns take precedence. These are the
+// recurring failure signatures from the 2026-07-20 session audit. A
+// real-world blocker that doesn't match any of these falls through to
+// "uncategorized" — better than empty, because empty means "we don't know
+// it's a blocker at all." See plans/2026-07-20-session-review-ten-sessions.md.
+var blockerPatterns = []struct {
+	pattern string
+	reason  string
+}{
+	{"queued for approval", "approval_timeout"},
+	{"assent window", "approval_timeout"},
+	{"cancel", "user_abandoned"},
+	{"close this session", "user_abandoned"},
+	{"lets just close", "user_abandoned"},
+	{"classifier flagged", "classifier_overreach"},
+	{"config_mutation", "classifier_overreach"},
+	{"refus", "model_refusal"}, // refuses/refused/refusal
+	{"empty response", "model_empty_response"},
+	{"no local knowledge", "missing_knowledge"},
+	{"can't run", "missing_capability"},
+	{"cannot run", "missing_capability"},
+	{"timeout", "tool_error"},
+	{"error", "tool_error"},
+}
+
+// deriveBlocker scans the last assistant message + the summary for known
+// failure signatures and returns the matching structured reason. Returns
+// "uncategorized" when outcome is partial/failed but no signature matched —
+// better than "" because the audit needs to know this WAS blocked, just for
+// an unknown reason. Returns "" for success outcomes (caller checks first).
+func deriveBlocker(ctx context.Context, s *store, sessionID, summary string) string {
+	// Pull the last assistant text — that's where the agent's parting
+	// words explain why it didn't finish.
+	var lastText string
+	_ = s.pool.QueryRow(ctx, `
+		SELECT content::text FROM agent_messages
+		WHERE session_id = $1 AND role = 'assistant'
+		ORDER BY created_at DESC LIMIT 1`, sessionID).Scan(&lastText)
+	haystack := strings.ToLower(lastText + " " + summary)
+	for _, p := range blockerPatterns {
+		if strings.Contains(haystack, p.pattern) {
+			return p.reason
+		}
+	}
+	return "uncategorized"
+}
+
 // hadEntityWriteback checks whether this session called update_entity_attributes
 // or create_relationship — used by complete_task to warn the agent when it
 // forgot to persist entity facts (the #1 cause of knowledge graph drift).