feat: remove tmux edit popup support for Claude Code

Claude Code CLI now supports Ctrl+G to open the prompt in EDITOR
(like OpenAI Codex CLI), making the built-in hexai-tmux-edit agent
profile redundant.

- Remove internal/tmuxedit/claude_agent.go and its tests
- Update builtinAgents() to exclude claude; built-ins are now: cursor, amp, aider
- Update all documentation (README, docs/tmux.md, docs/usage.md, docs/configuration.md)
- Update config.toml.example to reflect new agent list

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

3 files changed, 9 insertions, 13 deletions

diff --git a/docs/configuration.md b/docs/configuration.md
index 013d2c8..645d2ca 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -140,6 +140,6 @@ Hexai Tmux Edit (popup editor)
   submit_keys = "Enter"
   ```
 
-- Built-in agents: `claude`, `cursor`, `amp`, `aider`. See [config.toml.example](../config.toml.example) for all fields.
-- OpenAI Codex CLI uses its native external editor shortcut (`Ctrl+G`) instead of a built-in `tmux_edit` agent profile.
+- Built-in agents: `cursor`, `amp`, `aider`. See [config.toml.example](../config.toml.example) for all fields.
+- OpenAI Codex CLI and Claude Code CLI use their native external editor shortcut (`Ctrl+G`) instead of a built-in `tmux_edit` agent profile.
 - Tmux keybinding: `bind e run-shell -b "cd '#{pane_current_path}' && hexai-tmux-edit --pane '#{pane_id}'"`
diff --git a/docs/tmux.md b/docs/tmux.md
index a1628cb..ba024e3 100644
--- a/docs/tmux.md
+++ b/docs/tmux.md
@@ -71,9 +71,9 @@ window_minutes = 60  # default 60; min 1, max 1440
 
 ## Popup editor for AI agent prompts
 
-`hexai-tmux-edit` opens your `$EDITOR` in a tmux popup to compose longer prompts when working with AI CLI agents (Claude Code, Cursor, Amp, Aider, etc.).
+`hexai-tmux-edit` opens your `$EDITOR` in a tmux popup to compose longer prompts when working with AI CLI agents (Cursor, Amp, Aider, etc.).
 
-OpenAI Codex CLI already supports editing in an external editor via `Ctrl+G`, so it does not need a built-in `hexai-tmux-edit` agent profile.
+OpenAI Codex CLI and Claude Code CLI both support editing in an external editor natively via `Ctrl+G`, so neither needs a built-in `hexai-tmux-edit` agent profile.
 
 ![Popup editor in action](tmux-edit-popup.png)
 
@@ -94,7 +94,6 @@ Then press `prefix + e` in any pane running an AI agent. Hexai auto-detects the
 See the [configuration guide](configuration.md) for customizing popup dimensions and agent patterns, or the [usage guide](usage.md) for the full workflow description.
 
 **Input mode notes**: Each agent uses different clearing methods based on their input handling:
-- **Claude Code**: Uses Emacs/readline keybindings (`C-a C-k`)
 - **Cursor**: Uses simple backspace clearing (`End BSpace*200`)
 - **Amp**: Uses Emacs/readline keybindings (`C-u`)
 - **Aider**: Uses Emacs/readline keybindings (`C-u`)
diff --git a/docs/usage.md b/docs/usage.md
index 8824a44..0786a00 100644
--- a/docs/usage.md
+++ b/docs/usage.md
@@ -250,9 +250,9 @@ Tips:
 
 `hexai-tmux-edit` opens your `$EDITOR` in a tmux popup for composing longer AI agent prompts. It captures existing prompt text from the target pane, pre-fills the editor, and sends the edited text back via `tmux send-keys`.
 
-This is useful when working with AI CLI agents (Claude Code, Cursor, Amp, Aider, etc.) and you need to compose a longer, multi-line prompt with the comfort of your regular editor (spellcheck, search/replace, etc.).
+This is useful when working with AI CLI agents (Cursor, Amp, Aider, etc.) and you need to compose a longer, multi-line prompt with the comfort of your regular editor (spellcheck, search/replace, etc.).
 
-OpenAI Codex CLI is not a built-in `hexai-tmux-edit` agent. Codex already supports editing in an external editor via `Ctrl+G`.
+OpenAI Codex CLI and Claude Code CLI are not built-in `hexai-tmux-edit` agents. Both support editing in an external editor natively via `Ctrl+G`.
 
 ### Supported agents
 
@@ -261,17 +261,14 @@ Built-in agent detection (auto-detected from pane content, checked in order):
 1. **Cursor** -- detects box-drawing UI `│ →` or footer `/ commands · @ files`
    - Clears with: `End BSpace*200` (backspace method)
    - Prompt pattern: Extracts from last `│...│` box
-2. **Claude Code** -- detects `❯` prompt symbol, "claude code", or "anthropic"
-   - Clears with: `C-a C-k` (Emacs/readline style)
-   - Prompt pattern: Extracts from last section between `─────` rules
-3. **Amp** -- detects "amp" or "sourcegraph" in pane (TUI mode)
+2. **Amp** -- detects "amp" or "sourcegraph" in pane (TUI mode)
    - Clears with: `C-u` (Emacs/readline style)
    - Prompt pattern: Extracts from `│...│` box UI (similar to Cursor)
-4. **Aider** -- detects "aider" in pane
+3. **Aider** -- detects "aider" in pane
    - Clears with: `C-u` (Emacs/readline style)
    - Prompt pattern: Shell-style `> prompt`
 
-**Detection order matters**: Cursor and Claude are checked first to avoid false positives. For example, Cursor may display "Claude 4.5 Sonnet" as its model name, but Cursor's distinctive `│ →` box UI is matched first.
+**Detection order matters**: Cursor is checked first to avoid false positives. For example, Cursor may display "Claude 4.5 Sonnet" as its model name, but Cursor's distinctive `│ →` box UI is matched first.
 
 Additional agents can be added via `[tmux_edit.agents]` in config.toml without code changes.