feat(ux): visual improvements for list tree, graph, and show commands

bd list --tree:
- Use actual parent-child dependencies instead of dotted ID hierarchy
- Treat epic dependencies as parent-child relationships
- Sort children by priority (P0 first)
- Fix tree display in daemon mode with read-only store access

bd graph:
- Add --all flag to show dependency graph of all open issues
- Add --compact flag for tree-style rendering (reduces 44+ lines to 13)
- Fix "needs:N" cognitive noise by using semantic colors
- Add blocks:N indicator with semantic red coloring

bd show:
- Tufte-aligned header with status icon, priority, and type badges
- Add glamour markdown rendering with auto light/dark mode detection
- Cap markdown line width at 100 chars for readability
- Mute entire row for closed dependencies (work done, no attention needed)

Design system:
- Add shared status icons (○ ◐ ● ✓ ❄) with semantic colors
- Implement priority colors: P0 red, P1 orange, P2 muted gold, P3-P4 neutral
- Add TrueColor profile for distinct hex color rendering
- Type badges for epic (purple) and bug (red)

Design principles:
- Semantic colors only for actionable items
- Closed items fade (muted gray)
- Icons > text labels for better scanability

Co-Authored-By: SageOx <ox@sageox.ai>

cmd/bd/list_helpers_test.go

@@ -57,8 +57,8 @@ func TestListFormatPrettyIssue_BadgesAndDefaults(t *testing.T) {
 	if !strings.Contains(out, "bd-1") || !strings.Contains(out, "Hello") {
 		t.Fatalf("unexpected output: %q", out)
 	}
-	if !strings.Contains(out, "[BUG]") {
-		t.Fatalf("expected BUG badge: %q", out)
+	if !strings.Contains(out, "[bug]") {
+		t.Fatalf("expected bug badge: %q", out)
 	}
 }