Add Bubble Tea TUI with interactive treemap

Cell canvas renderer with frame cache and a perceptual 256-colour
quantizer; responsive geometry (large/medium/small/too-small);
squarified treemap with nested previews, LOD grouping, category
colouring and adaptive labels; spatial arrow navigation with stable
NodeID selection; zoom and breadcrumbs; modal system (info, help,
confirm, save); list, file-type, top-N, scan-info, duplicate and
comparison views; live search/filter; mouse support; move-to-trash.

internal/tui/run.go

@@ -0,0 +1,59 @@
+package tui
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	tea "charm.land/bubbletea/v2"
+	"github.com/charmbracelet/colorprofile"
+
+	"github.com/andydixon/mapsize/internal/inventory"
+	"github.com/andydixon/mapsize/internal/scan"
+	"github.com/andydixon/mapsize/internal/snapshot"
+	"github.com/andydixon/mapsize/internal/textutil"
+)
+
+var profiles = map[string]colorprofile.Profile{
+	"truecolor": colorprofile.TrueColor, "24bit": colorprofile.TrueColor,
+	"256": colorprofile.ANSI256, "16": colorprofile.ANSI, "none": colorprofile.ASCII,
+}
+
+func saveFile(path string, t *inventory.Tree) error { return snapshot.SaveFile(path, t) }
+
+// Run starts the interactive UI. The terminal is restored on every exit
+// path: normal quit, Ctrl+C, errors and panics (Bubble Tea recovers panics
+// in Update/View; scanner goroutine panics are routed here via
+// scan.OnPanic and reported after the terminal is restored).
+func Run(opts Options) error {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	s, t, err := opts.Start(ctx)
+	if err != nil {
+		return err
+	}
+	m := newModel(opts, s, t, cancel)
+	var popts []tea.ProgramOption
+	if p, ok := profiles[opts.Color]; ok {
+		m.profile, m.forced = p, true
+		popts = append(popts, tea.WithColorProfile(p))
+	} else if opts.Color != "" && opts.Color != "auto" {
+		return fmt.Errorf("invalid --color %q (auto, truecolor, 256, 16, none)", opts.Color)
+	}
+	p := tea.NewProgram(m, popts...)
+	prev := scan.OnPanic
+	scan.OnPanic = func(v any, stack []byte) {
+		p.Send(fatalMsg{v, stack})
+		select {} // park the broken goroutine; the program is quitting
+	}
+	defer func() { scan.OnPanic = prev }()
+
+	_, err = p.Run()
+	cancel()
+	if m.fatal != nil {
+		fmt.Fprintf(os.Stderr, "mapsize: internal error in scanner: %s\n\n%s\n",
+			textutil.Sanitize(fmt.Sprint(m.fatal.v)), m.fatal.stack)
+		return fmt.Errorf("scanner crashed")
+	}
+	return err
+}