Merge pull request #73 from LazyBachelor/LPM-138

LPM-138 Refactor Tui with composable modals and use canvas

Refactors the TUI (dashboard + kanban) to use a shared, composable modal system with canvas-based overlay rendering, while consolidating styling into internal/style and expanding issue interactions (e.g., comments).

Changes:

Introduces a new pkg/tui/modal system (manager/stack + multiple modal types) and overlays modals using Lipgloss compositor layers.
Refactors dashboard/kanban views and input handling to use the modal manager + focus manager instead of per-modal boolean state.
Consolidates TUI styling by moving from pkg/tui/styles to internal/style and updates components to use the new style package; adds a shared footer renderer.

pkg/tui/modal/focus.go

@@ -0,0 +1,143 @@
+package modal
+
+// FocusArea represents a distinct focusable area in the UI
+type FocusArea int
+
+const (
+	FocusNone FocusArea = iota
+	FocusList
+	FocusDetail
+	FocusColumn1
+	FocusColumn2
+	FocusColumn3
+	FocusColumn4
+)
+
+// FocusManager handles focus state across different UI areas.
+// It provides a clean separation of focus concerns from modal state.
+type FocusManager struct {
+	currentArea FocusArea
+	areas       map[FocusArea]bool
+}
+
+// NewFocusManager creates a new focus manager with all areas disabled by default
+func NewFocusManager() *FocusManager {
+	return &FocusManager{
+		currentArea: FocusNone,
+		areas:       make(map[FocusArea]bool),
+	}
+}
+
+// SetCurrent sets the currently focused area
+func (f *FocusManager) SetCurrent(area FocusArea) {
+	f.currentArea = area
+}
+
+// Current returns the currently focused area
+func (f *FocusManager) Current() FocusArea {
+	return f.currentArea
+}
+
+// IsFocused returns true if the given area is currently focused
+func (f *FocusManager) IsFocused(area FocusArea) bool {
+	return f.currentArea == area
+}
+
+// IsListFocused returns true if any list area is focused
+func (f *FocusManager) IsListFocused() bool {
+	return f.currentArea == FocusList ||
+		f.currentArea == FocusColumn1 ||
+		f.currentArea == FocusColumn2 ||
+		f.currentArea == FocusColumn3 ||
+		f.currentArea == FocusColumn4
+}
+
+// IsDetailFocused returns true if the detail area is focused
+func (f *FocusManager) IsDetailFocused() bool {
+	return f.currentArea == FocusDetail
+}
+
+// EnableArea marks an area as available for focus
+func (f *FocusManager) EnableArea(area FocusArea) {
+	f.areas[area] = true
+}
+
+// DisableArea marks an area as unavailable for focus
+func (f *FocusManager) DisableArea(area FocusArea) {
+	f.areas[area] = false
+	if f.currentArea == area {
+		f.currentArea = FocusNone
+	}
+}
+
+// IsAreaEnabled returns true if the area is enabled
+func (f *FocusManager) IsAreaEnabled(area FocusArea) bool {
+	return f.areas[area]
+}
+
+// Next moves focus to the next enabled area
+func (f *FocusManager) Next() {
+	areas := []FocusArea{FocusList, FocusDetail}
+	f.cycleFocus(areas)
+}
+
+// Previous moves focus to the previous enabled area
+func (f *FocusManager) Previous() {
+	areas := []FocusArea{FocusDetail, FocusList}
+	f.cycleFocus(areas)
+}
+
+// NextColumn moves focus to the next column (for kanban)
+func (f *FocusManager) NextColumn() {
+	areas := []FocusArea{FocusColumn1, FocusColumn2, FocusColumn3, FocusColumn4}
+	f.cycleFocus(areas)
+}
+
+// PreviousColumn moves focus to the previous column (for kanban)
+func (f *FocusManager) PreviousColumn() {
+	areas := []FocusArea{FocusColumn4, FocusColumn3, FocusColumn2, FocusColumn1}
+	f.cycleFocus(areas)
+}
+
+// cycleFocus finds the next enabled area in the given order
+func (f *FocusManager) cycleFocus(areas []FocusArea) {
+	// Find current position
+	startIdx := -1
+	for i, area := range areas {
+		if area == f.currentArea {
+			startIdx = i
+			break
+		}
+	}
+
+	// Search for next enabled area
+	for i := 1; i <= len(areas); i++ {
+		idx := (startIdx + i) % len(areas)
+		if idx < 0 {
+			idx += len(areas)
+		}
+		if f.areas[areas[idx]] {
+			f.currentArea = areas[idx]
+			return
+		}
+	}
+}
+
+// ToggleDetail toggles between list and detail focus
+func (f *FocusManager) ToggleDetail() {
+	if f.currentArea == FocusDetail {
+		f.currentArea = FocusList
+	} else {
+		f.currentArea = FocusDetail
+	}
+}
+
+// Reset clears the current focus
+func (f *FocusManager) Reset() {
+	f.currentArea = FocusNone
+}
+
+// CanHandleKey returns true if the current focus area can handle keyboard input
+func (f *FocusManager) CanHandleKey() bool {
+	return f.currentArea != FocusNone
+}