docs: Update HANDOFF with chat layout integration session

Author: josephwecker

HANDOFF.md

@@ -1,118 +1,68 @@
 # Handoff Notes for Next Agent
 
 **Last Updated:** 2025-12-18
-**Current State:** Multi-line input fully working with dynamic expansion
+**Current State:** Chat command fully integrated with Layout::Composed
 
 ---
 
-## This Session: Multi-line Input Polish
+## This Session: Chat Layout Integration
 
-Completed comprehensive improvements to Pinax multi-line input handling. All fixes are in the core library, not just the demo.
+Integrated `Pinax::Layout::Composed` into the chat command so that multi-line input
+with dynamic expansion works in all modes (streaming and non-streaming).
 
-### What Was Implemented
+### What Changed
 
-| Feature | Files Changed | Notes |
-|---------|---------------|-------|
-| Multi-line rendering | `input/renderer.rb` | Newlines display as separate lines, word wrapping |
-| Dynamic input expansion | `layout/composed.rb`, `prompt.rb` | Input grows, history scrolls up |
-| Input collapse after submit | `layout/composed.rb`, `prompt.rb` | Returns to initial size |
-| Arrow key navigation | `prompt.rb`, `input.rb` | Left/right/home/end work with Kitty enhanced format |
-| Bottom border | `layout/composed.rb`, `region_builder.rb` | Border between input and status |
-| Scroll region fixes | `layout/composed.rb` | Properly reset/reactivate on resize |
+| Change | Before | After |
+|--------|--------|-------|
+| Layout class | `Pinax::Layout` | `Pinax::Layout::Composed` |
+| Layout creation | Only when `--stream` | Always |
+| Prompt init | `input_row: @layout&.input_row` | `layout: @layout` |
+| Output routing | `warn`/`$stdout.puts` fallbacks | All through layout |
 
-### Key Technical Details
+**Key insight:** The `--stream` flag should control API behavior (SSE vs blocking),
+not whether you get a decent input experience. Now both modes have identical TUI.
 
-**Kitty Enhanced Arrow Format:**
-- Arrow keys send `\e[1;modifier:event_typeX` (not CSI u)
-- Event type 3 = release (must be ignored)
-- Updated regex to accept `:` in parameter section
+### Files Changed
 
-**Dynamic Resize Flow:**
-1. `Renderer#rows_needed` calculates visual lines needed
-2. `Prompt#maybe_resize_input!` triggers resize when needed
-3. `Layout#resize_input!` scrolls history, repositions regions, updates scroll region
-4. `Renderer#base_row=` and `max_rows=` update cached positions
-
-**Input Collapse:**
-- `Layout#reset_input_size!` shrinks back to initial height
-- Clears old border line before repositioning (prevents relic in history)
-- Called from `Prompt#finalize_display` after submit
-
----
-
-## Demo Usage
-
-```bash
-./bin/layout-multiline-demo
-```
-
-- Type text, Enter for new lines
-- Shift+Enter to submit
-- Left/Right/Home/End for cursor movement
-- Input area expands as needed, collapses after submit
+- `lib/autopax/commands/chat/interactive.rb` - 24 insertions, 36 deletions
 
 ---
 
 ## Architecture
 
-The Pinax library provides a complete terminal UI toolkit:
+The chat command now uses the full Pinax stack:
 
 ```ruby
-# With Layout integration (recommended)
-layout = Pinax::Layout::Composed.new
-layout.setup!(input_lines: 4)  # top_border + input + bottom_border + status
+# setup_layout creates layout unconditionally
+@layout = Pinax::Layout::Composed.new
+@layout.setup!(input_lines: 4)
+@layout.status = status_line
 
-prompt = Pinax::Prompt.new(layout: layout)
-text = prompt.capture(prompt: '> ')  # Dynamic expansion handled automatically
+# Prompt gets the layout for dynamic expansion
+prompt = Pinax::Prompt.new(layout: @layout)
+text = prompt.capture(prompt: '> ')
 
-layout.history("[user] #{text}")
-layout.teardown!
+# All output through layout
+@layout << "[user] #{text}"
+@layout << "[assistant] #{response}"
 ```
 
-### Module Structure
-
-```
-lib/pinax/
-├── input.rb              # Key codes, Kitty protocol parsing
-├── input/
-│   ├── buffer.rb         # Text buffer with cursor
-│   └── renderer.rb       # Terminal rendering (relative/absolute modes)
-├── layout/
-│   ├── composed.rb       # DECSTBM-based layout with regions
-│   ├── region_builder.rb # Region creation and sizing
-│   └── position_accessors.rb
-├── prompt.rb             # Multi-line input with Shift+Enter submit
-└── region/               # Region types (scrollable, fixed, dynamic)
-```
+Both streaming and blocking modes now have:
+- Shift+Enter to submit, Enter for newlines
+- Dynamic input area expansion as you type
+- DECSTBM scroll regions (history scrolls, input/status fixed)
+- Status bar with model and token counts
 
 ---
 
-## Next Steps
-
-### Priority: Chat Command Integration
-The chat command (`lib/autopax/commands/chat/interactive.rb`) uses older Pinax patterns:
-- Uses `Pinax::Layout` instead of `Pinax::Layout::Composed`
-- Passes `input_row:` to Prompt instead of `layout:` (no dynamic expansion)
-- Streaming disabled by default, layout only created when streaming
+## Remaining Polish
 
-**To integrate new features:**
-```ruby
-# Change from:
-@layout = Pinax::Layout.new
-prompt = Pinax::Prompt.new(input_row: @layout&.input_row)
-
-# To:
-@layout = Pinax::Layout::Composed.new
-@layout.setup!(input_lines: 4)
-prompt = Pinax::Prompt.new(layout: @layout)
-```
-
-### Remaining Polish
 - [ ] Up/down arrow navigation within multi-line text
 - [ ] Write Kitty harness tests for multi-line input
 - [ ] Terminal resize support (SIGWINCH)
 
-### Future
+## Future
+
 - [ ] Multiple status lines support
 - [ ] Consider extracting Pinax as standalone gem
 - [ ] Terminal capability detection
@@ -124,7 +74,7 @@ prompt = Pinax::Prompt.new(layout: @layout)
 ```bash
 ./autopax dev test                    # 884 examples, 0 failures
 ./autopax dev format --check          # Minor pre-existing offenses
-INTEGRATION=true ./autopax dev test spec/integration/pinax/  # Visual tests
+INTEGRATION=true ./autopax dev test spec/integration/pinax/  # Visual tests pass
 ```
 
-Branch: `main` (all changes committed)
+Branch: `main` (all changes committed and merged)