fix(analyze): add darwin build tag to all platform-specific files

All files in cmd/analyze/ are macOS-only but several were missing the
//go:build darwin constraint. On Linux (e.g. CodeQL CI), Go compiled
these files without the types defined in main.go (which had the tag),
causing undefined symbol errors for dirEntry, fileEntry, scanResult,
cacheEntry, historyEntry and model.

- Add //go:build darwin to heap.go, cache.go, scanner.go, cleanable.go,
  delete.go, format.go, constants.go and all *_test.go files

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

cmd/analyze/analyze_test.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (

cmd/analyze/cache.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (

cmd/analyze/cleanable.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (

cmd/analyze/constants.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import "time"

cmd/analyze/delete.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (

cmd/analyze/delete_test.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (

cmd/analyze/format.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (

cmd/analyze/format_test.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (
@@ -20,7 +22,7 @@ func TestRuneWidth(t *testing.T) {
 		{"CJK ideograph", '語', 2},
 		{"Full-width number", '１', 2},
 		{"ASCII space", ' ', 1},
-		{"Tab", '\t', 1},
+		{"Tab", '	', 1},
 	}
 
 	for _, tt := range tests {

cmd/analyze/heap.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 // entryHeap is a min-heap of dirEntry used to keep Top N largest entries.

cmd/analyze/heap_test.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (

cmd/analyze/main_stub.go

@@ -0,0 +1,13 @@
+//go:build !darwin
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func main() {
+	fmt.Fprintln(os.Stderr, "analyze is only supported on macOS")
+	os.Exit(1)
+}

cmd/analyze/scanner.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (

cmd/analyze/scanner_test.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (

cmd/analyze/test_helpers_test.go

@@ -1,3 +1,5 @@
+//go:build darwin
+
 package main
 
 import (