fix(tui): replace bare arrow keys with leader-key session navigation

Session child/parent navigation now uses ctrl+x + hjkl consistently,
removing bare arrow key bindings that conflicted with macOS window
management and terminal cursor movement.

Closes: #88
Constraint: ctrl+x j (first child) already used leader-key pattern
Rejected: keeping arrows as alternates | still conflicts with OS
Confidence: high
Scope-risk: narrow

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: bobbyjohnstx

packages/tinycode/src/cli/cmd/tui/config/keybind.ts

@@ -97,9 +97,9 @@ export const Definitions = {
   session_toggle_timestamps: keybind("none", "Toggle message timestamps"),
   session_toggle_generic_tool_output: keybind("none", "Toggle generic tool output"),
   session_child_first: keybind("<leader>j", "Go to first child session"),
-  session_child_cycle: keybind("right", "Go to next child session"),
-  session_child_cycle_reverse: keybind("left", "Go to previous child session"),
-  session_parent: keybind("up,<leader>k", "Go to parent session"),
+  session_child_cycle: keybind("<leader>l", "Go to next child session"),
+  session_child_cycle_reverse: keybind("<leader>h", "Go to previous child session"),
+  session_parent: keybind("<leader>k", "Go to parent session"),
   session_pin_toggle: keybind("ctrl+f", "Pin or unpin session in the session list"),
   session_quick_switch_1: keybind("<leader>1", "Switch to session in quick slot 1"),
   session_quick_switch_2: keybind("<leader>2", "Switch to session in quick slot 2"),