docs: Enhance testing guidelines to include interactive UI testing

Align key bindings with project brief

AGENTS.md

@@ -0,0 +1,26 @@
+# AGENTS
+
+## Memory Bank Requirements
+- **Always read the Memory Bank before starting any task.**
+- Memory Bank lives in `memory-bank/` and contains:
+  - `projectbrief.md`
+  - `productContext.md`
+  - `systemPatterns.md`
+  - `techContext.md`
+  - `activeContext.md`
+  - `progress.md`
+- The Memory Bank is the single source of project context. If a user requests **update memory bank**, review every file in the directory before making changes.
+- After significant work or when insights are gained, update `activeContext.md` and `progress.md`. Create additional files in `memory-bank/` when useful for organizing new documentation.
+
+## Development Guidelines
+- **Language:** Go using modules.
+- **Formatting:** run `gofmt -w` on modified Go files.
+- **Testing:** practice TDD and run `go test ./...` before committing, also Test the Application interactively, to ensure the UI is also correct.
+- **Linting:** run `golangci-lint run` when available.
+- **Structure:** keep application code inside `internal/` packages and follow existing patterns for `core`, `tui`, and `utils`.
+- **Error Handling:** return errors instead of panicking and provide clear messages.
+
+## Commit Process
+- Ensure Memory Bank is updated when project state changes.
+- Run the formatting, lint, and test commands above.
+- Commit only when the worktree is clean and all commands pass.

CLAUDE.md

@@ -0,0 +1,87 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is a Go TUI application for managing `/etc/hosts` files using the Bubble Tea framework. The app provides a two-pane interface (list view + detail view) for viewing, editing, and managing host entries with features like activation/deactivation, sorting, and DNS resolution.
+
+## Architecture
+
+The codebase follows a clean architecture pattern with separation of concerns:
+
+- `cmd/hosts/main.go` - Entry point that parses `/etc/hosts` and launches the TUI
+- `internal/core/` - Core business logic and data models
+  - `models.go` - Data structures for HostEntry and HostsFile with validation
+  - `parser.go` - Hosts file parsing, formatting, and writing with intelligent formatting detection
+- `internal/tui/` - Bubble Tea TUI components
+  - `model.go` - Main Bubble Tea model with pane navigation and mode management
+  - `view.go` - Rendering logic for the two-pane interface
+  - `update.go` - Message handling and state updates
+- `tests/` - Test files following TDD approach
+
+## Key Technical Patterns
+
+### Data Models
+- `HostEntry` represents individual host entries with IP, hostname, aliases, comments, and active status
+- `HostsFile` contains collections of entries with methods for searching, adding, and removing
+- All models include validation methods and proper error handling
+
+### TUI Architecture
+- Uses Bubble Tea's Model-View-Update pattern
+- Two-pane layout with list and detail views
+- Mode switching between ViewMode and EditMode
+- Pane focus management (listPane/detailPane)
+
+### File Operations
+- Intelligent formatting detection preserves original hosts file style
+- Atomic file operations with backup creation
+- Proper validation before writing changes
+
+## Development Commands
+
+### Build and Run
+```bash
+go run cmd/hosts/main.go
+go build -o hosts cmd/hosts/main.go
+```
+
+### Testing
+```bash
+go test ./...                    # Run all tests
+go test ./tests/                 # Run tests in tests directory
+go test -v ./internal/core/      # Run core package tests with verbose output
+go test -cover ./...             # Run tests with coverage
+```
+
+### Dependencies
+Key dependencies are managed via `go.mod`:
+- Bubble Tea framework for TUI
+- Bubbles for common components
+- Lip Gloss for styling
+- testify for test assertions
+
+## Important Implementation Details
+
+### Hosts File Parsing
+The parser in `internal/core/parser.go` handles:
+- Active and inactive (commented) entries
+- Inline comments preservation
+- Intelligent formatting detection (tabs vs spaces)
+- IPv4/IPv6 address validation
+- RFC-compliant hostname validation
+
+### TUI Navigation
+- Tab/Shift+Tab for pane switching
+- Arrow keys for list navigation
+- Space for toggling entry activation
+- 'q' to quit application
+
+### Error Handling
+- Comprehensive validation at model level
+- Parse warnings collection during file parsing
+- Graceful error recovery in TUI operations
+
+## Memory Bank Integration
+
+This project uses Cline's Memory Bank system located in `memory-bank/` directory. The project brief and context files provide additional architectural context and development history. Always consult these files when making significant changes to understand the project's evolution and design decisions.

internal/tui/update.go

@@ -18,13 +18,13 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			} else {
 				m.focus = listPane
 			}
-		case "e":
+		case "ctrl+e":
 			if m.mode == ViewMode {
 				m.mode = EditMode
 			} else {
 				m.mode = ViewMode
 			}
-		case "a":
+		case " ":
 			if m.mode == EditMode {
 				if entry := m.SelectedEntry(); entry != nil {
 					entry.Active = !entry.Active
@@ -34,7 +34,7 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			}
 		case "up", "k":
 			if m.focus == detailPane {
-				m.detail.LineUp(1)
+				m.detail.ScrollUp(1)
 			} else {
 				m.list, cmd = m.list.Update(msg)
 				m.refreshDetail()
@@ -42,7 +42,7 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			return m, cmd
 		case "down", "j":
 			if m.focus == detailPane {
-				m.detail.LineDown(1)
+				m.detail.ScrollDown(1)
 			} else {
 				m.list, cmd = m.list.Update(msg)
 				m.refreshDetail()

memory-bank/activeContext.md

@@ -24,8 +24,8 @@
 - ✅ **Parser integration** loading `/etc/hosts` into the UI
 
 ### Phase 3: Edit Mode (IN PROGRESS)
-- 🔄 **Edit mode toggle** via 'e' key with status bar indication
+- 🔄 **Edit mode toggle** via 'ctrl+e' key with status bar indication
-- 🔄 **Entry activation toggle** using 'a' key
+- 🔄 **Entry activation toggle** using spacebar
 - 🔄 **Model tests** covering edit mode behavior
 
 ### Parser Capabilities Achieved

memory-bank/progress.md

@@ -80,6 +80,7 @@
 - **Active work**: Expand edit mode with file integration and advanced editing
 - **Blockers**: None - comprehensive parser foundation with 54 tests completed
 - **Parser status**: Production-ready with all safety features implemented
+- **Key bindings updated**: `ctrl+e` for edit mode, spacebar to toggle entries
 
 ### Development Readiness
 - ✅ **Architecture designed**: Clear technical approach documented

memory-bank/projectbrief.md

@@ -29,6 +29,17 @@ The user can:
 - Use DNS-based resolution for hostnames
 - Quickly update IP addresses
 
+Key Bindings:
+- `ctrl`+`e`: Change to edit mode
+- `e`: Edit the currently selected hostname entry
+- `space`: Entry activation toggle
+- `shift`+`up`/`down`: Move the selected entry up or down
+- `i` Sort by IP addresses
+- `n` Sort by (the first) hostname
+- `ctrl`+`s`: Save
+- `c` To open the tool configuration
+- `?` or `h`: Display help about all Key Bindings
+
 The program will operate in **view-only mode** by default and require explicit entry into **edit mode**, at which point it will request elevated (sudo) permissions until editing is disabled.
 
 The project uses:

tests/tui_test.go

@@ -72,12 +72,12 @@ func TestEditModeToggleAndActivation(t *testing.T) {
 	m := tui.NewModel(hf)
 
 	// enter edit mode
-	nm, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'e'}})
+	nm, _ := m.Update(tea.KeyMsg{Type: tea.KeyCtrlE})
 	m = nm.(tui.Model)
 	assert.Equal(t, tui.EditMode, m.Mode())
 
 	// toggle active state of first entry
-	nm, _ = m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'a'}})
+	nm, _ = m.Update(tea.KeyMsg{Type: tea.KeySpace})
 	m = nm.(tui.Model)
 	assert.False(t, m.SelectedEntry().Active)