feat: add import resolution with Xenia-style thunk stubs (M8)

- resolve_imports() rewrites PE import records in-place:
  - Variable slots: 0xD000BEEF | (ordinal & 0xFFF) << 16
  - Thunk stubs: li r3, 0 / li r4, <ordinal> / mtspr CTR, r11 / bctr
- New -r/--resolve-imports flag on the extract command
- Without the flag, extraction is unchanged (byte-for-byte identical)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/integration.rs

@@ -552,6 +552,113 @@ fn test_decode_import_names_resolved() {
     assert!(has_dbg_break, "should find DbgBreakPoint import");
 }
 
+#[test]
+fn test_resolve_imports_variables() {
+    let data = sample_data();
+    let xex = xex2tractor::parse(&data).unwrap();
+    let mut pe_image = extract::extract_pe_image(&data, &xex).unwrap();
+
+    let summary = imports::resolve_imports(&mut pe_image, &xex).unwrap();
+    assert!(summary.variables_written > 0);
+    assert!(summary.thunks_written > 0);
+    assert_eq!(
+        summary.total,
+        summary.variables_written + summary.thunks_written
+    );
+
+    // Check first xam.xex variable at PE offset 0x600 (ordinal 0x028C)
+    // Should be 0xD000BEEF | (0x28C & 0xFFF) << 16 = 0xD28CBEEF
+    let val = u32::from_be_bytes([
+        pe_image[0x600],
+        pe_image[0x601],
+        pe_image[0x602],
+        pe_image[0x603],
+    ]);
+    assert_eq!(val, 0xD28CBEEF, "variable slot should have 0xD000BEEF pattern");
+}
+
+#[test]
+fn test_resolve_imports_thunks() {
+    let data = sample_data();
+    let xex = xex2tractor::parse(&data).unwrap();
+    let mut pe_image = extract::extract_pe_image(&data, &xex).unwrap();
+
+    imports::resolve_imports(&mut pe_image, &xex).unwrap();
+
+    // Check first xam.xex thunk at PE offset 0x84DA7C (ordinal 0x028C)
+    let off = 0x0084DA7C;
+    let w0 = u32::from_be_bytes([pe_image[off], pe_image[off + 1], pe_image[off + 2], pe_image[off + 3]]);
+    let w1 = u32::from_be_bytes([pe_image[off + 4], pe_image[off + 5], pe_image[off + 6], pe_image[off + 7]]);
+    let w2 = u32::from_be_bytes([pe_image[off + 8], pe_image[off + 9], pe_image[off + 10], pe_image[off + 11]]);
+    let w3 = u32::from_be_bytes([pe_image[off + 12], pe_image[off + 13], pe_image[off + 14], pe_image[off + 15]]);
+
+    assert_eq!(w0, 0x38600000, "thunk word 0 should be li r3, 0");
+    assert_eq!(w1, 0x3880028C, "thunk word 1 should be li r4, 0x028C");
+    assert_eq!(w2, 0x7D6903A6, "thunk word 2 should be mtspr CTR, r11");
+    assert_eq!(w3, 0x4E800420, "thunk word 3 should be bctr");
+}
+
+#[test]
+fn test_extract_without_resolve_unchanged() {
+    let data = sample_data();
+    let xex = xex2tractor::parse(&data).unwrap();
+    let pe_unresolved = extract::extract_pe_image(&data, &xex).unwrap();
+
+    // Without resolve, variable at 0x600 should be the raw descriptor
+    let val = u32::from_be_bytes([
+        pe_unresolved[0x600],
+        pe_unresolved[0x601],
+        pe_unresolved[0x602],
+        pe_unresolved[0x603],
+    ]);
+    assert_eq!(val, 0x0000028C, "unresolved variable should be raw descriptor");
+
+    // Thunk word 0 should be the record marker, not a PPC instruction
+    let off = 0x0084DA7C;
+    let w0 = u32::from_be_bytes([
+        pe_unresolved[off],
+        pe_unresolved[off + 1],
+        pe_unresolved[off + 2],
+        pe_unresolved[off + 3],
+    ]);
+    assert_eq!(w0, 0x0100028C, "unresolved thunk word 0 should be record marker");
+}
+
+#[test]
+fn test_resolve_imports_pe_still_valid() {
+    let data = sample_data();
+    let xex = xex2tractor::parse(&data).unwrap();
+    let mut pe_image = extract::extract_pe_image(&data, &xex).unwrap();
+
+    imports::resolve_imports(&mut pe_image, &xex).unwrap();
+
+    // PE verification should still pass (MZ + PE headers untouched)
+    assert!(extract::verify_pe_image(&pe_image).is_ok());
+}
+
+#[test]
+fn test_cli_extract_resolve_imports() {
+    let path = format!("{}/tests/data/default.xex", env!("CARGO_MANIFEST_DIR"));
+    let output_path = format!(
+        "{}/target/test_resolve_output.exe",
+        env!("CARGO_MANIFEST_DIR")
+    );
+    let _ = std::fs::remove_file(&output_path);
+
+    let output = std::process::Command::new(env!("CARGO_BIN_EXE_xex2tractor"))
+        .args(["extract", "-r", &path, &output_path])
+        .output()
+        .expect("failed to run xex2tractor");
+
+    assert!(output.status.success(), "CLI extract -r should succeed");
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    assert!(stdout.contains("Resolved"), "should print resolution summary");
+    assert!(stdout.contains("variables"), "should mention variables");
+    assert!(stdout.contains("thunks"), "should mention thunks");
+
+    let _ = std::fs::remove_file(&output_path);
+}
+
 #[test]
 fn test_cli_inspect_shows_resolved_imports() {
     let path = format!("{}/tests/data/default.xex", env!("CARGO_MANIFEST_DIR"));