Unified editing: merge color editing into Edit Lines via Tab mode #259

Summary

Major TUI overhaul that unifies the editing experience with consistent navigation patterns throughout. What started as a proposal to merge color editing into Edit Lines grew into a comprehensive rethink of TUI navigation.

Problem (original)

Editing a widget's color required navigating: MainMenu → Edit Colors → LineSelector → ColorMenu → (edit) → ESC × 3 → MainMenu. The "Edit Lines" and "Edit Colors" top-level split put the same objects behind different doors.

Additionally, the Rules Editor was a full-screen overlay that removed all context of the widget list. Navigation was inconsistent across screens — some wrapped, some didn't; some used ← Back menu items, some used ESC only; keybinds were case-sensitive in some screens and case-insensitive in others.

What Was Built

1. Unified Color Editing (Tab mode)

• Press Tab to switch between items mode and color mode on any widget
• Inline color editing: ←→ cycle, hex, ANSI256, bold, fg/bg toggle
• Removed separate "Edit Colors" menu entirely
• Deleted ColorMenu.tsx and color-menu/mutations.ts

2. Accordion Rules Editor

• Press → on a widget to expand its rules inline below it
• Rules use the same interaction patterns as widgets: ↑↓ navigate, Tab for color/property mode, Enter for focus mode
• Deleted full-screen RulesEditor.tsx overlay — replaced by accordion
• Empty rules show placeholder: (no rules — press 'a' to add)

3. Consistent Tree Navigation

• → drills in, ← drills out at every level: LineSelector → ItemsEditor → Rules → ConditionEditor
• Enter = focus/edit mode at every level: ↑↓ reorders, ←→ edits properties
• ESC peels back one layer — never skips levels
• ↑↓ wraps at top/bottom everywhere
• Removed all "← Back" menu items — ← arrow handles back navigation

4. Polish

• Exit confirmation when unsaved changes exist
• Case-insensitive keybinds across all screens
• "Enter to edit" replaces "Enter to move" for better discoverability
• PowerlineSeparatorEditor refactored to same Enter/focus pattern

Navigation Model

Implementation

All work is on the feat/unified-editing branch. See PR #261 for the full diff.

Tags for rollback points:

• unified-editing-phase1 — color mode added, legacy Edit Colors still present
• unified-editing-phase2 — legacy Edit Colors removed
• accordion-rules-editor — accordion replaces full-screen overlay