fix(ci): keep the release candidate green on Rust 1.100

Cargo 1.100 lays build artifacts out per unit, so a rustc call for
codewhale-runtime carries about 330 search-path arguments (45K characters).
sccache expands the argument file cargo hands it and spawns rustc with the full
line, which Windows refuses past 32767 characters (os error 206). Windows legs
of the release-artifacts and nightly workflows no longer enable sccache, as
ci.yml already does for its Windows test steps; artifacts are unchanged.

Rustc 1.100 reports the map_err on TestBackend's Infallible error as
unreachable code under -D warnings; the probe test now builds the terminal with
expect.

codewhale-engine declared arboard but never uses it; the TUI keeps its own.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

.github/workflows/nightly.yml

@@ -73,7 +73,7 @@ jobs:
         id: sccache
         continue-on-error: true
       - name: Enable sccache
-        if: steps.sccache.outcome == 'success'
+        if: steps.sccache.outcome == 'success' && runner.os != 'Windows'
         shell: bash
         run: |
           {

.github/workflows/release-artifacts.yml

@@ -178,7 +178,7 @@ jobs:
         id: sccache
         continue-on-error: true
       - name: Enable sccache
-        if: steps.sccache.outcome == 'success'
+        if: steps.sccache.outcome == 'success' && runner.os != 'Windows'
         shell: bash
         run: |
           {

Cargo.lock

@@ -1179,7 +1179,6 @@ dependencies = [
  "agent-client-protocol",
  "agent-client-protocol-schema",
  "anyhow",
- "arboard",
  "async-stream",
  "async-trait",
  "axum",

crates/engine/Cargo.toml

@@ -219,9 +219,6 @@ libc = "0.2"
 windows-sys = { version = "0.61.2", features = ["Wdk_Storage_FileSystem", "Win32_System_IO", "Win32_Foundation", "Win32_Security", "Win32_Security_Authorization", "Win32_Security_Isolation", "Win32_Storage_FileSystem", "Win32_System_LibraryLoader", "Win32_System_Pipes", "Win32_System_Threading", "Win32_System_SystemServices", "Win32_System_WindowsProgramming"] }
 
 
-[target.'cfg(any(target_os = "macos", target_os = "windows", all(target_os = "linux", not(target_env = "ohos"))))'.dependencies]
-arboard = { version = "3.4", features = ["wayland-data-control"] }
-
 [target.'cfg(not(target_env = "ohos"))'.dependencies]
 portable-pty = "0.9"
 

crates/tui/src/tui/ui/terminal.rs

@@ -1104,13 +1104,13 @@ mod screen_mode_tests {
                 Ok(())
             },
             || {
-                Terminal::with_options(
+                Ok(Terminal::with_options(
                     TestBackend::new(20, 6),
                     ratatui::TerminalOptions {
                         viewport: ratatui::Viewport::Inline(3),
                     },
                 )
-                .map_err(|err| io::Error::other(err.to_string()))
+                .expect("inline test terminal"))
             },
         )
         .expect("a successful probe must switch");