Remove hexai-tmux-edit popup editor featurev0.42.0

The tmux popup editor and its per-agent detection (Cursor/Amp/Aider)
added maintenance surface without enough use to justify it; Codex and
Claude Code already support external-editor mode natively via Ctrl+G.
Drops internal/tmuxedit, cmd/hexai-tmux-edit, the [tmux_edit] config
schema, the Mage build target, and all related docs/README mentions.

Bump version to 0.42.0.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

1 files changed, 0 insertions, 58 deletions

diff --git a/internal/tmuxedit/cursor_agent.go b/internal/tmuxedit/cursor_agent.go
deleted file mode 100644
index ebea38e..0000000
--- a/internal/tmuxedit/cursor_agent.go
+++ /dev/null
@@ -1,58 +0,0 @@
-package tmuxedit
-
-import (
-	"regexp"
-)
-
-// cursorAgent handles Cursor's distinctive box-drawing │ → prompt │ UI.
-// Cursor uses a text field (not vim), so clearing is done with End + bulk
-// backspace. Multi-line prompts are entered with Shift-Enter within the box.
-type cursorAgent struct{ baseAgent }
-
-// newCursorAgent returns a cursorAgent with the default configuration.
-// Detect by the box structure or "/ commands" footer. Checked first because
-// cursor panes often show model names like "Claude 4.5 Sonnet".
-func newCursorAgent() *cursorAgent {
-	return &cursorAgent{baseAgent{
-		name:          "cursor",
-		displayName:   "Cursor",
-		detectPattern: `(│\s*→|/ commands · @ files)`,
-		promptPat:     `(?m)│\s*→?\s*(.+?)\s*│\s*$`,
-		stripPatterns: []string{"INSERT", "Add a follow-up", "ctrl+c to stop"},
-		clearFirst:    true,
-		clearKeys:     "End BSpace*200",
-		newlineKeys:   "S-Enter",
-		submitKeys:    "Enter",
-	}}
-}
-
-// ExtractPrompt extracts the prompt text from the last contiguous │...│ block
-// in the pane. This avoids picking up earlier command-review or dialog boxes
-// that also use box-drawing characters.
-func (c *cursorAgent) ExtractPrompt(paneContent string) string {
-	if c.promptPat == "" {
-		return ""
-	}
-	re, err := regexp.Compile(c.promptPat)
-	if err != nil {
-		return ""
-	}
-	allMatches := matchPromptLines(re, paneContent)
-	if len(allMatches) == 0 {
-		return ""
-	}
-	return joinLastContiguousBlock(allMatches, c.stripPatterns)
-}
-
-// ClearInput sends End + 200 backspaces to clear Cursor's text field.
-// Cursor's input is a standard text field, not vim.
-func (c *cursorAgent) ClearInput(paneID string) error {
-	if !c.clearFirst || c.clearKeys == "" {
-		return nil
-	}
-	if err := c.deps.sendClearSequence(paneID, c.clearKeys); err != nil {
-		return err
-	}
-	c.deps.sleep()
-	return nil
-}