feat(context): reasoning-thread continuity, L3 doc filtering, and gate hardening

Threads reasoning_content across inference calls and journal renders, filters
markdown noise out of L3 repo-knowledge retrieval, adds PlanLinter H3 checks,
and tightens filesystem tool output/dir-listing behavior surfaced by prior
live QA (see project_readloop_campaign memory).

apps/tui-go/internal/app/view.go

@@ -790,6 +790,10 @@ func (m Model) buildTranscriptRows(w int) ([]string, []int) {
 	t := m.theme
 	msgs := m.routerMessages[m.selectedID]
 	var rows []string
+	// Prepend the live execution plan card when the session has locked plan stages.
+	if planRows := m.planCardLines(); len(planRows) > 0 {
+		rows = append(rows, planRows...)
+	}
 	msgStart := make([]int, len(msgs)) // first row index of each message, for scroll-to-selection
 	for mi, e := range msgs {
 		msgStart[mi] = len(rows)
@@ -847,6 +851,53 @@ func (m Model) buildTranscriptRows(w int) ([]string, []int) {
 	return rows, msgStart
 }
 
+// planCardLines renders the live execution plan card for the selected session.
+func (m Model) planCardLines() []string {
+	t := m.theme
+	s := m.session(m.selectedID)
+	if s == nil || len(s.PlanStages) == 0 {
+		return nil
+	}
+	goal := strings.TrimSpace(s.PlanGoal)
+	var out []string
+	if goal != "" {
+		out = append(out, t.span(goal, t.P.Faint))
+	}
+	stageLabel := "stage"
+	if len(s.PlanStages) != 1 {
+		stageLabel = "stages"
+	}
+	out = append(out, t.span("Plan \u00b7 "+itoa(len(s.PlanStages))+" "+stageLabel, t.P.Accent))
+	idW := 0
+	for _, ps := range s.PlanStages {
+		if len(ps.ID) > idW {
+			idW = len(ps.ID)
+		}
+	}
+	for _, ps := range s.PlanStages {
+		var badge, badgeStyle string
+		var badgeColor color.Color
+		switch ps.Status {
+		case PlanPending:
+			badge = "\u25cb"
+			badgeColor = t.P.Faint
+		case PlanRunning:
+			badge = "\u25cf"
+			badgeColor = t.P.Accent
+		case PlanCompleted:
+			badge = "\u2713"
+			badgeColor = t.P.OK
+		case PlanFailed:
+			badge = "\u2717"
+			badgeColor = t.P.Bad
+		}
+		badgeStyle = t.span(badge, badgeColor)
+		rest := t.span("  "+padRaw(ps.ID, idW), t.P.Fg)
+		out = append(out, "  "+badgeStyle+rest)
+	}
+	return out
+}
+
 func (m Model) eventRows(w, h int) []string {
 	t := m.theme
 	header := lipgloss.NewStyle().Foreground(t.P.Accent).Background(t.P.Bg).Bold(true).Render("event stream") +