feat: add export database and import record decoding (M7)

- New src/exports.rs: embeds doc/xbox360_exports.md via include_str!
  and lazily parses it into a lookup table (OnceLock). Covers 2,913
  exports across xboxkrnl.exe, xam.xex, and xbdm.xex.
- New src/imports.rs: decodes import records from extracted PE images
  by reading the u32 at each import address, extracting record type
  (variable/thunk) and ordinal, and resolving against the export DB.
- inspect command now shows a full resolved imports table with names.

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

tests/integration.rs

@@ -1,6 +1,8 @@
 use xex2tractor::crypto;
+use xex2tractor::exports;
 use xex2tractor::extract;
 use xex2tractor::header::{ModuleFlags, XEX2_MAGIC};
+use xex2tractor::imports::{self, ImportRecordType};
 use xex2tractor::optional::{CompressionInfo, CompressionType, EncryptionType, SystemFlags};
 use xex2tractor::security::{ImageFlags, MediaFlags, RegionFlags};
 
@@ -440,3 +442,137 @@ fn test_cli_extract_shows_format_info() {
 
     let _ = std::fs::remove_file(&output_path);
 }
+
+// ── Export database tests ────────────────────────────────────────────────────
+
+#[test]
+fn test_export_db_total_count() {
+    assert_eq!(exports::total_count(), 2913);
+}
+
+#[test]
+fn test_export_db_module_counts() {
+    assert_eq!(exports::module_count("xboxkrnl.exe"), 922);
+    assert_eq!(exports::module_count("xam.xex"), 1736);
+    assert_eq!(exports::module_count("xbdm.xex"), 255);
+}
+
+#[test]
+fn test_export_db_lookup_known() {
+    let info = exports::lookup("xboxkrnl.exe", 0x009).unwrap();
+    assert_eq!(info.name, "ExAllocatePool");
+    assert!(info.is_function);
+}
+
+#[test]
+fn test_export_db_lookup_unknown_ordinal() {
+    assert!(exports::lookup("xboxkrnl.exe", 0xFFFF).is_none());
+}
+
+// ── Import record decoding tests ─────────────────────────────────────────────
+
+#[test]
+fn test_decode_import_records() {
+    let data = sample_data();
+    let xex = xex2tractor::parse(&data).unwrap();
+    let pe_image = extract::extract_pe_image(&data, &xex).unwrap();
+
+    let resolved = imports::decode_import_records(&pe_image, &xex).unwrap();
+
+    // Sample has 104 xam.xex + 294 xboxkrnl.exe = 398 total import records
+    assert_eq!(resolved.len(), 398);
+}
+
+#[test]
+fn test_decode_import_record_types() {
+    let data = sample_data();
+    let xex = xex2tractor::parse(&data).unwrap();
+    let pe_image = extract::extract_pe_image(&data, &xex).unwrap();
+
+    let resolved = imports::decode_import_records(&pe_image, &xex).unwrap();
+
+    let variables = resolved
+        .iter()
+        .filter(|r| r.record.record_type == ImportRecordType::Variable)
+        .count();
+    let thunks = resolved
+        .iter()
+        .filter(|r| r.record.record_type == ImportRecordType::Thunk)
+        .count();
+
+    // Every import should be either variable or thunk
+    assert_eq!(variables + thunks, resolved.len());
+    // Both types should be present
+    assert!(variables > 0);
+    assert!(thunks > 0);
+}
+
+#[test]
+fn test_decode_import_alternating_pattern() {
+    let data = sample_data();
+    let xex = xex2tractor::parse(&data).unwrap();
+    let pe_image = extract::extract_pe_image(&data, &xex).unwrap();
+
+    let resolved = imports::decode_import_records(&pe_image, &xex).unwrap();
+
+    // Check first few xam.xex entries: variable, thunk, variable, thunk, ...
+    let xam: Vec<_> = resolved.iter().filter(|r| r.library == "xam.xex").collect();
+    assert!(xam.len() >= 4);
+    assert_eq!(xam[0].record.record_type, ImportRecordType::Variable);
+    assert_eq!(xam[1].record.record_type, ImportRecordType::Thunk);
+    assert_eq!(xam[2].record.record_type, ImportRecordType::Variable);
+    assert_eq!(xam[3].record.record_type, ImportRecordType::Thunk);
+
+    // Variable and thunk for same function share the same ordinal
+    assert_eq!(xam[0].record.ordinal, xam[1].record.ordinal);
+}
+
+#[test]
+fn test_decode_import_names_resolved() {
+    let data = sample_data();
+    let xex = xex2tractor::parse(&data).unwrap();
+    let pe_image = extract::extract_pe_image(&data, &xex).unwrap();
+
+    let resolved = imports::decode_import_records(&pe_image, &xex).unwrap();
+
+    // Most imports should resolve to known names
+    let named = resolved.iter().filter(|r| r.export.is_some()).count();
+    assert!(
+        named > resolved.len() / 2,
+        "expected most imports to resolve, got {named}/{}",
+        resolved.len()
+    );
+
+    // Check a specific known import is present
+    let has_dbg_break = resolved.iter().any(|r| {
+        r.export
+            .as_ref()
+            .is_some_and(|e| e.name == "DbgBreakPoint")
+    });
+    assert!(has_dbg_break, "should find DbgBreakPoint import");
+}
+
+#[test]
+fn test_cli_inspect_shows_resolved_imports() {
+    let path = format!("{}/tests/data/default.xex", env!("CARGO_MANIFEST_DIR"));
+
+    let output = std::process::Command::new(env!("CARGO_BIN_EXE_xex2tractor"))
+        .args(["inspect", &path])
+        .output()
+        .expect("failed to run xex2tractor");
+
+    assert!(output.status.success());
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    assert!(
+        stdout.contains("Resolved Imports"),
+        "inspect should show resolved imports section"
+    );
+    assert!(
+        stdout.contains("xboxkrnl.exe"),
+        "inspect should show xboxkrnl.exe imports"
+    );
+    assert!(
+        stdout.contains("xam.xex"),
+        "inspect should show xam.xex imports"
+    );
+}