fix(tui): use iterm2 word characters for fullscreen double-click selection (#11340)

- add iterm2's default word characters (`+ \ ~ _ .`) to fullscreen
double-click selection
([source](7f4ff73972/sources/Settings/iTermPreferences.m (L743)))
- `~/...`, `~/.pi/...`, `~\...`, `foo+bar` now select whole
- add regression cases for `~`, `.`, `\`, `+`
- fixes #10980

packages/tui/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed fullscreen double-click selection splitting paths and tokens at `~`, `.`, `\`, and `+`. Word characters now match iTerm2's defaults ([#10980](https://github.com/earendil-works/pi/issues/10980))
+
 ## [1.4.0] - 2026-10-21
 
 ### Added

packages/tui/src/tui-alt-screen.ts

@@ -81,8 +81,9 @@ const MAX_CACHED_OFFSCREEN_KITTY_DECODED_BYTES = 64 * 1024 * 1024;
 const DOUBLE_CLICK_INTERVAL_MS = 500;
 const COPY_ERROR_FLASH_DURATION_MS = 5000;
 // Regular mode delegates double-click selection to the terminal emulator. Fullscreen owns mouse selection,
-// so mirror common terminal word-selection behavior by keeping paths and kebab-case tokens whole.
-const TERMINAL_WORD_SELECTION_JOINERS = new Set(["/", "-"]);
+// so it uses iTerm2's default "characters considered part of a word" set:
+// https://github.com/gnachman/iTerm2/blob/7f4ff739721f95d0b93003d8701c4523a7edf261/sources/Settings/iTermPreferences.m#L743
+const TERMINAL_WORD_SELECTION_JOINERS = new Set(["/", "-", "+", "\\", "~", "_", "."]);
 const wordSegmenter = getWordSegmenter();
 
 interface CachedKittyImage {

packages/tui/test/tui-alt-screen.test.ts

@@ -1544,6 +1544,9 @@ describe("TuiAltScreen", () => {
 		for (const { line, needle } of [
 			{ line: "extensions/starline/fixed-editor/compositor.ts", needle: "starline" },
 			{ line: "earendil-works/pi-tui", needle: "works" },
+			{ line: "~/.pi/agent/settings.json", needle: "agent" },
+			{ line: "~\\Documents\\pi", needle: "Documents" },
+			{ line: "foo+bar", needle: "bar" },
 		]) {
 			const copied: string[] = [];
 			const terminal = new RecordingTerminal(80, 1);