feat: disasm popup, symbol separation, context menu improvements, RVA fixes

- Add Fadec x86 disassembler with hover popup for FuncPtr/void Pointer nodes
- Separate pointer symbol from address: // prefix, green comment coloring,
  independent hover/click zones (address triggers popup, symbol is passive)
- Fix RVA margin and inline local offset for pointer-expanded vtable children
  using ptrBase field threaded through composition
- Expand multi-select context menu with quick-convert, duplicate, copy address
- Remove Edit Value from hex node context menu
- Fix heatmap flickering on hex nodes (remove per-byte alternation)
- Fix popup repositioning when moving mouse between lines
- Truncate disasm popup to 6 lines with ... indicator
- Add BUILD_UI_TESTS option to skip widget tests on headless CI
- Add test_disasm with 35 test cases for disassembly and hex dump
- Add KUSER_SHARED_DATA example .rcx file

third_party/fadec/encode-test.c

@@ -0,0 +1,62 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include <fadec-enc.h>
+
+
+static
+void
+print_hex(const uint8_t* buf, size_t len)
+{
+    for (size_t i = 0; i < len; i++)
+        printf("%02x", buf[i]);
+}
+
+static
+int
+test(uint8_t* buf, const char* name, uint64_t mnem, uint64_t op0, uint64_t op1, uint64_t op2, uint64_t op3, const void* exp, size_t exp_len)
+{
+    memset(buf, 0, 16);
+
+    uint8_t* inst = buf;
+    int res = fe_enc64(&inst, mnem, op0, op1, op2, op3);
+    if ((res != 0) != (exp_len == 0)) goto fail;
+    if (inst - buf != (ptrdiff_t) exp_len) goto fail;
+    if (memcmp(buf, exp, exp_len)) goto fail;
+
+    return 0;
+
+fail:
+    printf("Failed case %s:\n", name);
+    printf("  Exp (%2zu): ", exp_len);
+    print_hex(exp, exp_len);
+    printf("\n  Got (%2zd): ", inst - buf);
+    print_hex(buf, inst - buf);
+    printf("\n");
+    return -1;
+}
+
+#define TEST2(str, exp, exp_len, mnem, flags, op0, op1, op2, op3, ...) test(buf, str, FE_ ## mnem|flags, op0, op1, op2, op3, exp, exp_len)
+#define TEST1(str, exp, ...) TEST2(str, exp, sizeof(exp)-1, __VA_ARGS__, 0, 0, 0, 0, 0)
+#define TEST(exp, ...) failed |= TEST1(#__VA_ARGS__, exp, __VA_ARGS__)
+
+int
+main(int argc, char** argv)
+{
+    (void) argc; (void) argv;
+
+    int failed = 0;
+    uint8_t buf[16];
+
+    // VSIB encoding doesn't differ for this API
+#define FE_MEMV FE_MEM
+#define FE_PTR(off) ((intptr_t) buf + (off))
+#define FLAGMASK(flags, mask) (flags | FE_MASK(mask & 7))
+#include "encode-test.inc"
+
+    puts(failed ? "Some tests FAILED" : "All tests PASSED");
+    return failed ? EXIT_FAILURE : EXIT_SUCCESS;
+}