feat: scanner panel with signature/value search, rescan, address delegate

- Signature mode (IDA-style patterns with wildcards) and value mode (typed exact match)
- Async scan engine with progress, cancel support
- Re-scan updates all results with unified progress (single-pass read + table build)
- Previous value column appears after first re-scan
- WinDbg backtick address format with dimmed leading zeros (AddressDelegate)
- Inline editing: address expressions navigate, value edits write to provider
- Right-click context menu: Copy Address, Copy Value, Go to Address
- Auto-sized columns, themed buttons with icons, dynamic combo width
- 49 UI tests covering scan, rescan, editing, theming, progress completion

src/scanner.h

@@ -0,0 +1,85 @@
+#pragma once
+#include "providers/provider.h"
+#include <QObject>
+#include <QByteArray>
+#include <QString>
+#include <QVector>
+#include <QFutureWatcher>
+#include <atomic>
+#include <memory>
+
+namespace rcx {
+
+// ── Scan request / result ──
+
+struct ScanRequest {
+    QByteArray pattern;             // literal bytes to match
+    QByteArray mask;                // 0xFF = must match, 0x00 = wildcard
+
+    bool filterExecutable = false;  // only scan +x regions
+    bool filterWritable   = false;  // only scan +w regions
+
+    int alignment  = 1;             // 1 = every byte, 4 = dword, 8 = qword
+    int maxResults = 50000;
+};
+
+struct ScanResult {
+    uint64_t   address;
+    QString    regionModule;
+    QByteArray scanValue;       // cached bytes at scan/update time
+    QByteArray previousValue;   // value before last update
+};
+
+// ── Value scan types ──
+
+enum class ValueType {
+    Int8, Int16, Int32, Int64,
+    UInt8, UInt16, UInt32, UInt64,
+    Float, Double,
+    Vec2, Vec3, Vec4,
+    UTF8, UTF16,
+    HexBytes
+};
+
+// ── Pattern parsing ──
+
+// Parse IDA-style signature string ("48 8B ?? 05") into pattern + mask.
+// Returns true on success. On failure, sets errorMsg.
+bool parseSignature(const QString& input, QByteArray& pattern, QByteArray& mask,
+                    QString* errorMsg = nullptr);
+
+// Serialize a typed value into raw bytes for exact-match scanning.
+// Returns true on success. On failure, sets errorMsg.
+bool serializeValue(ValueType type, const QString& input,
+                    QByteArray& pattern, QByteArray& mask,
+                    QString* errorMsg = nullptr);
+
+// Natural alignment for a value type (used as default alignment for value scans).
+int naturalAlignment(ValueType type);
+
+// ── Scan engine ──
+
+class ScanEngine : public QObject {
+    Q_OBJECT
+public:
+    explicit ScanEngine(QObject* parent = nullptr);
+
+    void start(std::shared_ptr<Provider> provider, const ScanRequest& req);
+    void abort();
+    bool isRunning() const;
+
+signals:
+    void progress(int percent);
+    void finished(QVector<ScanResult> results);
+    void error(QString message);
+
+private:
+    QVector<ScanResult> runScan(std::shared_ptr<Provider> prov, const ScanRequest& req);
+
+    std::atomic<bool> m_abort{false};
+    QFutureWatcher<QVector<ScanResult>>* m_watcher = nullptr;
+};
+
+} // namespace rcx
+
+Q_DECLARE_METATYPE(QVector<rcx::ScanResult>)