feat: add multi-session terminal support

ARCHITECTURE.md

@@ -129,22 +129,36 @@ vim.api.nvim_create_autocmd("CursorMoved", {
 -- Preserves selection context when switching to terminal
 ```
 
-### 6. Terminal Integration (`terminal.lua`)
+### 6. Terminal Integration (`terminal/`)
 
-Flexible terminal management with provider pattern:
+Flexible terminal management with provider pattern and centralized window management:
 
 ```lua
--- Snacks.nvim provider (preferred)
-if has_snacks then
-  Snacks.terminal.open(cmd, {
-    win = { position = "right", width = 0.3 }
-  })
-else
-  -- Native fallback
-  vim.cmd("vsplit | terminal " .. cmd)
-end
+-- Window manager singleton owns THE terminal window
+-- Providers only create buffers, window_manager displays them
+local window_manager = require("claudecode.terminal.window_manager")
+
+-- Display a buffer in the managed window (preserves user resizing)
+window_manager.display_buffer(bufnr, focus)
+
+-- Snacks.nvim provider creates buffer, delegates window to manager
+local term = Snacks.terminal.open(cmd, opts)
+vim.api.nvim_win_close(term.win, false)  -- Close snacks' window
+window_manager.display_buffer(term.buf, true)  -- Use our window
+
+-- Native provider creates buffer without window
+local bufnr = vim.api.nvim_create_buf(false, true)
+vim.fn.termopen(cmd, { env = env })
+window_manager.display_buffer(bufnr, true)
 ```
 
+Key features:
+
+- **Single window**: All sessions share one terminal window
+- **Buffer switching**: `nvim_win_set_buf()` preserves window size
+- **Session management**: Multiple Claude sessions with tab-like switching
+- **Window preservation**: User resizing persists across session switches
+
 ## Key Implementation Patterns
 
 ### Thread Safety
@@ -199,7 +213,15 @@ lua/claudecode/
 ├── tools/init.lua        # MCP tool registry
 ├── diff.lua              # Native diff support
 ├── selection.lua         # Selection tracking
-├── terminal.lua          # Terminal management
+├── session.lua           # Multi-session state management
+├── terminal.lua          # Terminal orchestration
+├── terminal/             # Terminal providers
+│   ├── window_manager.lua # Singleton window management
+│   ├── snacks.lua        # Snacks.nvim provider
+│   ├── native.lua        # Native Neovim terminal
+│   ├── external.lua      # External terminal apps
+│   ├── tabbar.lua        # Session tab bar UI
+│   └── osc_handler.lua   # Terminal title detection
 └── lockfile.lua          # Discovery files
 ```
 

CHANGELOG.md

@@ -4,6 +4,9 @@
 
 ### Features
 
+- Multi-session terminal support with `:ClaudeCodeNew`, `:ClaudeCodeSessions`, `:ClaudeCodeSwitch`, `:ClaudeCodeCloseSession` commands
+- Tab bar UI with mouse support for session management (`terminal.tabs.*` configuration)
+- Smart ESC handling - double-tap ESC to exit terminal mode (`esc_timeout`, `keymaps.exit_terminal`)
 - External terminal provider to run Claude in a separate terminal ([#102](https://github.com/coder/claudecode.nvim/pull/102))
 - Terminal provider APIs: implement `ensure_visible` for reliability ([#103](https://github.com/coder/claudecode.nvim/pull/103))
 - Working directory control for Claude terminal ([#117](https://github.com/coder/claudecode.nvim/pull/117))
@@ -32,6 +35,10 @@
 
 ### Bug Fixes
 
+- Preserve terminal window size across session operations
+- Keep terminal window open when session exits with other sessions available
+- Fix cursor position when switching terminal sessions
+- Send selection updates on BufEnter event
 - Wrap ERROR/WARN logging in `vim.schedule` to avoid fast-event context errors ([#54](https://github.com/coder/claudecode.nvim/pull/54))
 - Native terminal: do not wipe Claude buffer on window close ([#60](https://github.com/coder/claudecode.nvim/pull/60))
 - Native terminal: respect `auto_close` behavior ([#63](https://github.com/coder/claudecode.nvim/pull/63))

CLAUDE.md

@@ -288,22 +288,27 @@ require("claudecode").setup({
 
 The `diff_opts` configuration allows you to customize diff behavior:
 
+- `layout` ("vertical"|"horizontal", default: `"vertical"`) - Whether the diff panes open in a vertical or horizontal split.
 - `keep_terminal_focus` (boolean, default: `false`) - When enabled, keeps focus in the Claude Code terminal when a diff opens instead of moving focus to the diff buffer. This allows you to continue using terminal keybindings like `<CR>` for accepting/rejecting diffs without accidentally triggering other mappings.
 - `open_in_new_tab` (boolean, default: `false`) - Open diffs in a new tab instead of the current tab.
 - `hide_terminal_in_new_tab` (boolean, default: `false`) - When opening diffs in a new tab, do not show the Claude terminal split in that new tab. The terminal remains in the original tab, giving maximum screen estate for reviewing the diff.
+- `on_new_file_reject` ("keep_empty"|"close_window", default: `"keep_empty"`) - Behavior when rejecting a diff for a new file (where the old file did not exist).
+- Legacy aliases (still supported): `vertical_split` (maps to `layout`) and `open_in_current_tab` (inverse of `open_in_new_tab`).
 
 **Example use case**: If you frequently use `<CR>` or arrow keys in the Claude Code terminal to accept/reject diffs, enable this option to prevent focus from moving to the diff buffer where `<CR>` might trigger unintended actions.
 
 ```lua
 require("claudecode").setup({
   diff_opts = {
-    keep_terminal_focus = true,  -- If true, moves focus back to terminal after diff opens
-    open_in_new_tab = true,      -- Open diff in a separate tab
+    layout = "vertical", -- "vertical" or "horizontal"
+    keep_terminal_focus = true, -- If true, moves focus back to terminal after diff opens
+    open_in_new_tab = true, -- Open diff in a separate tab
     hide_terminal_in_new_tab = true, -- In the new tab, do not show Claude terminal
-    auto_close_on_accept = true,
-    show_diff_stats = true,
-    vertical_split = true,
-    open_in_current_tab = true,
+    on_new_file_reject = "keep_empty", -- "keep_empty" or "close_window"
+
+    -- Legacy aliases (still supported):
+    -- vertical_split = true,
+    -- open_in_current_tab = true,
   },
 })
 ```

DEVELOPMENT.md

@@ -153,6 +153,9 @@ vv netrw      # Start Neovim with built-in netrw configuration
 
 # List available configurations
 list-configs
+
+# Minimal repro environment (copies fixtures/repro/example into /tmp)
+repro
 ```
 
 **Example fixture structure** (`fixtures/my-integration/`):