Detect tests: honor RF_TEST_NO_DETECT_APPS in the Unix fallback too

Resolve-RfClaudeCliPath's macOS/Linux fallback unconditionally checked
/usr/local/bin/claude and /opt/homebrew/bin/claude, so on any dev box
with Claude Code installed the Pester "claude is nowhere" tests in
Detect.Tests.ps1 picked up the real binary and failed. The Windows
install-dir probe already respected RF_TEST_NO_DETECT_APPS=1 for
exactly this reason; the Unix branch was missed.

Add the same guard. New-RfIsolatedHome already sets the flag, so the
Detect tests inherit it; the Resolve / Test-RfHostClaudeCodeCli
BeforeEach blocks now only clear it on Windows (they need the
install-dir probe to fire against the fake APPDATA tree).

Pester on macOS dev box: 53/53 passing (was 51/53). Windows behavior
unchanged because the new guard sits inside `if Test-RfMacOS -or
Test-RfLinux`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: yeldarby

installer/lib/detect.ps1

@@ -135,7 +135,11 @@ function Resolve-RfClaudeCliPath {
     }
 
     # 4. macOS / Linux off-PATH install locations.
-    if (Test-RfMacOS -or Test-RfLinux) {
+    # Same suppression flag the Windows block uses, so the Pester suite's
+    # "no agents installed" tests pass on a dev Mac that has a real
+    # /usr/local/bin/claude.
+    if ((Test-RfMacOS) -or (Test-RfLinux)) {
+        if ($env:RF_TEST_NO_DETECT_APPS -eq '1') { return $null }
         $unixFallbacks = @()
         $share = Join-Path $HOME '.local/share/anthropic-claude/claude-code'
         if (Test-Path -LiteralPath $share) {

tests/pester/Detect.Tests.ps1

@@ -33,9 +33,13 @@ Describe 'Resolve-RfClaudeCliPath' {
         New-Item -ItemType Directory -Path $env:LOCALAPPDATA -Force | Out-Null
         # New-RfIsolatedHome sets RF_TEST_NO_DETECT_APPS=1 (desktop-app
         # suppression), but this Describe is *testing* the install-dir
-        # probe specifically. Clear the flag inside the controlled APPDATA
-        # so we exercise the code under test.
-        Remove-Item Env:RF_TEST_NO_DETECT_APPS -ErrorAction SilentlyContinue
+        # probe specifically. Clear the flag on Windows so we exercise the
+        # code under test. On Unix, leave it set so the macOS fallback
+        # (/usr/local/bin/claude, /opt/homebrew/bin/claude) doesn't pick up
+        # a real dev-box install during the "claude is nowhere" test.
+        if ($script:rfTestIsWindows) {
+            Remove-Item Env:RF_TEST_NO_DETECT_APPS -ErrorAction SilentlyContinue
+        }
     }
     AfterEach {
         $env:APPDATA      = $script:origAppData
@@ -175,7 +179,12 @@ Describe 'Test-RfHostClaudeCodeCli' {
         $env:LOCALAPPDATA = Join-Path $script:rfHome 'AppData/Local'
         New-Item -ItemType Directory -Path $env:APPDATA      -Force | Out-Null
         New-Item -ItemType Directory -Path $env:LOCALAPPDATA -Force | Out-Null
-        Remove-Item Env:RF_TEST_NO_DETECT_APPS -ErrorAction SilentlyContinue
+        # Clear on Windows so the install-dir probe runs against our fake
+        # APPDATA; leave set on Unix so a real /usr/local/bin/claude doesn't
+        # leak into "not installed" expectations.
+        if ($script:rfTestIsWindows) {
+            Remove-Item Env:RF_TEST_NO_DETECT_APPS -ErrorAction SilentlyContinue
+        }
     }
     AfterEach {
         $env:APPDATA      = $script:origAppData