refactor: Extract keybindings configuration to separate file (#438)

Keybindings have been moved from `.infer/config.yaml` to a dedicated
`.infer/keybindings.yaml` file.
The main config struct now hides keybindings from YAML serialization, a
new service handles loading/saving,
`infer init` seeds the new file, and environment variable processing was
relocated to config loading.

Closes #435

Author: edenreich

.infer/config.yaml

@@ -56,6 +56,7 @@ tools:
       - .infer/shortcuts/
       - .infer/agents.yaml
       - .infer/mcp.yaml
+      - .infer/keybindings.yaml
       - .git/
       - '*.env'
   bash:
@@ -329,230 +330,6 @@ conversation:
     interval: 0
 chat:
   theme: tokyo-night
-  keybindings:
-    enabled: false
-    bindings:
-      chat_enter_key_handler:
-        keys:
-          - enter
-        description: send message or insert newline
-        category: chat
-        enabled: true
-      clipboard_copy_text:
-        keys:
-          - ctrl+shift+c
-        description: copy text
-        category: clipboard
-        enabled: true
-      clipboard_paste_text:
-        keys:
-          - ctrl+v
-        description: paste text
-        category: clipboard
-        enabled: true
-      display_toggle_raw_format:
-        keys:
-          - ctrl+r
-        description: toggle raw/rendered markdown
-        category: display
-        enabled: true
-      display_toggle_thinking:
-        keys:
-          - ctrl+k
-        description: expand/collapse thinking blocks
-        category: display
-        enabled: true
-      display_toggle_todo_box:
-        keys:
-          - ctrl+t
-        description: toggle todo list
-        category: display
-        enabled: true
-      global_cancel:
-        keys:
-          - esc
-        description: cancel current operation
-        category: global
-        enabled: true
-      global_quit:
-        keys:
-          - ctrl+c
-        description: exit application
-        category: global
-        enabled: true
-      help_toggle_help:
-        keys:
-          - '?'
-        description: toggle help when input is empty
-        category: help
-        enabled: true
-      mode_cycle_agent_mode:
-        keys:
-          - shift+tab
-        description: cycle agent mode (Standard/Plan/Auto-Accept)
-        category: mode
-        enabled: true
-      navigation_go_back_in_time:
-        keys:
-          - esc,esc
-        description: go back in time to previous message (double ESC)
-        category: navigation
-        enabled: true
-      navigation_page_down:
-        keys:
-          - pgdn
-          - page_down
-        description: page down
-        category: navigation
-        enabled: true
-      navigation_page_up:
-        keys:
-          - pgup
-          - page_up
-        description: page up
-        category: navigation
-        enabled: true
-      navigation_scroll_down_half_page:
-        keys:
-          - shift+down
-        description: scroll down half page
-        category: navigation
-        enabled: true
-      navigation_scroll_to_bottom:
-        keys:
-          - end
-        description: scroll to bottom
-        category: navigation
-        enabled: true
-      navigation_scroll_to_top:
-        keys:
-          - home
-        description: scroll to top
-        category: navigation
-        enabled: true
-      navigation_scroll_up_half_page:
-        keys:
-          - shift+up
-        description: scroll up half page
-        category: navigation
-        enabled: true
-      plan_approval_plan_approval_accept:
-        keys:
-          - enter
-          - "y"
-        description: accept plan
-        category: plan_approval
-        enabled: true
-      plan_approval_plan_approval_accept_and_auto_approve:
-        keys:
-          - a
-        description: accept plan and enable auto-approve mode
-        category: plan_approval
-        enabled: true
-      plan_approval_plan_approval_left:
-        keys:
-          - left
-          - h
-        description: move selection left
-        category: plan_approval
-        enabled: true
-      plan_approval_plan_approval_reject:
-        keys:
-          - "n"
-        description: reject plan
-        category: plan_approval
-        enabled: true
-      plan_approval_plan_approval_right:
-        keys:
-          - right
-          - l
-        description: move selection right
-        category: plan_approval
-        enabled: true
-      selection_toggle_mouse_mode:
-        keys:
-          - ctrl+s
-        description: toggle mouse scrolling/text selection
-        category: selection
-        enabled: true
-      text_editing_backspace:
-        keys:
-          - backspace
-        description: delete character
-        category: text_editing
-        enabled: true
-      text_editing_delete_to_beginning:
-        keys:
-          - ctrl+u
-        description: delete to beginning of line
-        category: text_editing
-        enabled: true
-      text_editing_delete_word_backward:
-        keys:
-          - ctrl+w
-        description: delete word backward
-        category: text_editing
-        enabled: true
-      text_editing_history_down:
-        keys:
-          - down
-        description: navigate to next message in history
-        category: text_editing
-        enabled: true
-      text_editing_history_up:
-        keys:
-          - up
-        description: navigate to previous message in history
-        category: text_editing
-        enabled: true
-      text_editing_insert_newline_alt:
-        keys:
-          - alt+enter
-        description: insert newline
-        category: text_editing
-        enabled: true
-      text_editing_insert_newline_ctrl:
-        keys:
-          - ctrl+j
-        description: insert newline
-        category: text_editing
-        enabled: true
-      text_editing_move_cursor_left:
-        keys:
-          - left
-        description: move cursor left
-        category: text_editing
-        enabled: true
-      text_editing_move_cursor_right:
-        keys:
-          - right
-        description: move cursor right
-        category: text_editing
-        enabled: true
-      text_editing_move_to_beginning:
-        keys:
-          - ctrl+a
-        description: move cursor to beginning
-        category: text_editing
-        enabled: true
-      text_editing_move_to_end:
-        keys:
-          - ctrl+e
-        description: move cursor to end
-        category: text_editing
-        enabled: true
-      tools_background_shell:
-        keys:
-          - ctrl+b
-        description: move running bash command to background
-        category: tools
-        enabled: true
-      tools_toggle_tool_expansion:
-        keys:
-          - ctrl+o
-        description: expand/collapse tool results
-        category: tools
-        enabled: true
   status_bar:
     enabled: true
     indicators: