Fix crash when adding a new textures or audio examples (#6089)

rexm could crash and corrupt examples_list.txt when adding a new example in the textures category. This happened because the tool searched for the category name as plain text, and "text" happens to be part of "textures" (and shows up inside names like core_render_texture), so it sometimes found the wrong spot and inserted the new example in the middle of an unrelated line.

This fix makes the search look for the exact category boundary instead of just any matching text, so it always finds the right place. It also fixes a small out-of-bounds issue that could happen specifically with the audio category, since it's the last one in the list.

Tested by creating a new textures example and a new audio example, both now work correctly and the examples list stays intact.

tools/rexm/rexm.c

@@ -588,7 +588,7 @@ int main(int argc, char *argv[])
                 else if (TextIsEqual(exCategory, "text")) nextCategoryIndex = 4;
                 else if (TextIsEqual(exCategory, "models")) nextCategoryIndex = 5;
                 else if (TextIsEqual(exCategory, "shaders")) nextCategoryIndex = 6;
-                else if (TextIsEqual(exCategory, "audio")) nextCategoryIndex = 7;
+                else if (TextIsEqual(exCategory, "audio")) nextCategoryIndex = -1; // EOF, "audio" is the last category, avoid out-of-bounds exCategories[7] access
 
                 // Get required example info from example file header (if provided)
 
@@ -621,7 +621,13 @@ int main(int argc, char *argv[])
                 else
                 {
                     // Add example to collection, at the end of the category list
-                    int categoryIndex = TextFindIndex(exCollectionList, exCategories[nextCategoryIndex]);
+                    // NOTE: Search is anchored to "\n<category>;" (not just "<category>") to avoid
+                    // false-positive matches when one category name is a text-prefix of another
+                    // (e.g. "text" is a prefix of "textures", so a bare search for "text" matches
+                    // inside "core_render_texture" or at the start of the "textures" block instead
+                    // of the actual "text" category boundary, corrupting the collection list)
+                    int categoryIndex = TextFindIndex(exCollectionList, TextFormat("\n%s;", exCategories[nextCategoryIndex])) + 1;
+                    if (categoryIndex == 0) categoryIndex = (int)strlen(exCollectionList); // Category not found, fallback to EOF
                     memcpy(exCollectionListUpdated, exCollectionList, categoryIndex);
                     int textWritenSize = sprintf(exCollectionListUpdated + categoryIndex, TextFormat("%s;%s;%s;%s;%s;%i;%i;\"%s\";@%s\n",
                         exInfo->category, exInfo->name, starsText, exInfo->verCreated, exInfo->verUpdated, exInfo->yearCreated, exInfo->yearReviewed, exInfo->author, exInfo->authorGitHub));
@@ -1030,8 +1036,16 @@ int main(int argc, char *argv[])
 
                         // Find position to add new example on list, just before the following category
                         // Category order: core, shapes, textures, text, models, shaders, audio
+                        // NOTE: Search is anchored to "\n<category>;" (not just "\n<category>") to avoid
+                        // false-positive matches when one category name is a text-prefix of another
+                        // (e.g. "text" is a prefix of "textures", so a bare "\ntext" search matches the
+                        // START of the "textures" block instead of the actual "text" category boundary).
                         int exListNextCatIndex = -1;
-                        if (nextCatIndex != -1) exListNextCatIndex = TextFindIndex(exList, TextFormat("\n%s", exCategories[nextCatIndex])) + 1;
+                        if (nextCatIndex != -1)
+                        {
+                            exListNextCatIndex = TextFindIndex(exList, TextFormat("\n%s;", exCategories[nextCatIndex])) + 1;
+                            if (exListNextCatIndex == 0) exListNextCatIndex = exListLen; // Category not found, fallback to EOF
+                        }
                         else exListNextCatIndex = exListLen; // EOF
 
                         strncpy(exListUpdated, exList, exListNextCatIndex);