feat(tui-go): command-palette keybinds + configurable status bar

Palette: each command now shows its bare-key shortcut in a key column (and the filter
matches on it), so the palette teaches the shortcuts instead of hiding them.

Status bar: a new "status bar" palette command opens a toggle overlay to show/hide the
non-essential segments (current stage, session status, workspace path, model, last-event
clock, resource gauge); correx/connection/session-name/spinner stay. Choices persist
TUI-local in tui-prefs.json (JSON in the config dir — display state, kept out of the
shared/replayed server config) and reload on launch.

Also trims the in-session footer (drops stats/model — both reachable via `p cmds`) so it
no longer overflows + truncates `q quit` at ~100 cols after the transcript-nav additions.
Tests cover toggle→render gating and prefs persistence; verified via cmd/preview renders.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

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

@@ -0,0 +1,80 @@
+package app
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+)
+
+// prefs is the TUI's local, persisted preferences (display-only client state — kept out
+// of the server config, which is shared/replayed). Stored as JSON in the correx config dir.
+type prefs struct {
+	StatusbarHidden []string `json:"statusbarHidden"`
+}
+
+// statusSegment is one toggleable status-bar segment. The always-on segments (correx label,
+// connection, session name, spinner, background-updates) are not listed — they are load-bearing.
+type statusSegment struct{ id, label string }
+
+var statusSegments = []statusSegment{
+	{"stage", "current stage (⟐)"},
+	{"status", "session status"},
+	{"workspace", "workspace path (⌂)"},
+	{"model", "model name"},
+	{"clock", "last-event clock"},
+	{"gauge", "resource gauge"},
+}
+
+func prefsPath() string {
+	dir := os.Getenv("CORREX_CONFIG_HOME")
+	if dir == "" {
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return ""
+		}
+		dir = filepath.Join(home, ".config", "correx")
+	}
+	return filepath.Join(dir, "tui-prefs.json")
+}
+
+// loadStatusbarHidden reads the persisted hidden-segment set (best-effort: a missing or
+// corrupt file yields an empty set, i.e. everything shown).
+func loadStatusbarHidden() map[string]bool {
+	out := map[string]bool{}
+	path := prefsPath()
+	if path == "" {
+		return out
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return out
+	}
+	var p prefs
+	if json.Unmarshal(data, &p) == nil {
+		for _, id := range p.StatusbarHidden {
+			out[id] = true
+		}
+	}
+	return out
+}
+
+// saveStatusbarHidden writes the hidden set back to disk (best-effort; ignores IO errors so
+// a read-only home never crashes the UI). Order follows statusSegments for a stable file.
+func saveStatusbarHidden(hidden map[string]bool) {
+	path := prefsPath()
+	if path == "" {
+		return
+	}
+	var ids []string
+	for _, seg := range statusSegments {
+		if hidden[seg.id] {
+			ids = append(ids, seg.id)
+		}
+	}
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		return
+	}
+	if data, err := json.MarshalIndent(prefs{StatusbarHidden: ids}, "", "  "); err == nil {
+		_ = os.WriteFile(path, data, 0o644)
+	}
+}