refactor: render the shell in the client (#3487)

* feat: add opt-in client-rendered shell

* feat: add client-owned shell mouse controls

* feat: complete client-owned shell chrome

* feat: add client-owned shell settings and notifications

* feat: run client shell custom commands

* feat: render popup terminals in client shell

* feat: add client-owned scrollback and copy mode

* fix: preserve client worktree trust defaults

* feat: render startup diagnostics in client shell

* feat: render onboarding in client shell

* feat: render product announcements in client shell

* feat: render release notes in client shell

* feat: render mobile switcher in client shell

* feat: render kitty graphics in client shell

* fix: preserve client shell lifecycle coherence

* refactor: route client shell commands through endpoint connections

* refactor: make the client-rendered shell the default

* refactor: remove monolithic launch mode

* refactor: complete client-rendered shell cutover

* perf: retain client pane surface updates

* perf: scale retained pane surface updates

* perf: remove remote pane input latency

* test: make client shell checks platform-independent

* fix: prevent client timer starvation

* test: fix client shell platform gates

* test: accept retained surfaces in cross-area checks

* test: make client mode assertions platform-neutral

* fix: badge only outdated integrations

3 files changed, 41 insertions, 2 deletions

diff --git a/src/platform/fallback.rs b/src/platform/fallback.rs
index 64e5467b..7e14dcd8 100644
--- a/src/platform/fallback.rs
+++ b/src/platform/fallback.rs
@@ -220,8 +220,6 @@ pub fn open_url(_url: &str) -> std::io::Result<Option<std::process::Child>> {
 }
 
 /// Unsupported platform stub.
-// Windows does not wire clipboard-image bridging into semantic input yet.
-#[cfg_attr(windows, allow(dead_code))]
 pub fn read_clipboard_image() -> Option<ClipboardImage> {
     None
 }
diff --git a/src/platform/mod.rs b/src/platform/mod.rs
index 6323212a..fc80bc64 100644
--- a/src/platform/mod.rs
+++ b/src/platform/mod.rs
@@ -201,6 +201,14 @@ mod unix_common;
 #[cfg(unix)]
 pub(crate) use unix_common::{begin_cli_output, end_cli_output};
 
+#[cfg(not(windows))]
+pub(crate) fn replace_file(
+    source: &std::path::Path,
+    destination: &std::path::Path,
+) -> std::io::Result<()> {
+    std::fs::rename(source, destination)
+}
+
 #[cfg(not(unix))]
 pub(crate) fn begin_cli_output() {}
 
diff --git a/src/platform/windows.rs b/src/platform/windows.rs
index 413119ed..e63b8920 100644
--- a/src/platform/windows.rs
+++ b/src/platform/windows.rs
@@ -15,6 +15,39 @@ use std::{
 
 mod clipboard_image;
 
+pub(crate) fn replace_file(
+    source: &std::path::Path,
+    destination: &std::path::Path,
+) -> std::io::Result<()> {
+    use std::os::windows::ffi::OsStrExt;
+    use windows_sys::Win32::Storage::FileSystem::{
+        MoveFileExW, MOVEFILE_REPLACE_EXISTING, MOVEFILE_WRITE_THROUGH,
+    };
+
+    let source = source
+        .as_os_str()
+        .encode_wide()
+        .chain(std::iter::once(0))
+        .collect::<Vec<_>>();
+    let destination = destination
+        .as_os_str()
+        .encode_wide()
+        .chain(std::iter::once(0))
+        .collect::<Vec<_>>();
+    let moved = unsafe {
+        MoveFileExW(
+            source.as_ptr(),
+            destination.as_ptr(),
+            MOVEFILE_REPLACE_EXISTING | MOVEFILE_WRITE_THROUGH,
+        )
+    };
+    if moved == 0 {
+        Err(std::io::Error::last_os_error())
+    } else {
+        Ok(())
+    }
+}
+
 pub(crate) fn set_default_plugin_pane_pwd(
     _env: &mut Vec<(String, String)>,
     _cwd: &std::path::Path,