feat: implement file watching functionality in the filesystem module

- Added methods for file watching, including `watch`, `unwatch`, `unwatchAll`, `getWatchCount`, `pollWatch`, `getLastWatchPath`, and `getLastWatchRealPath`.
- Enhanced the `Filesystem` class to support monitoring file changes, allowing for real-time updates.
- Updated the `physfs` implementation to handle file watch targets and events.
- Improved documentation and added unit tests to validate the new file watching features.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/modules/ui/UIHost.cpp

@@ -0,0 +1,143 @@
+#include "ui/UIHost.h"
+#include "ui/Widget.h"
+
+namespace eve::ui {
+namespace {
+
+uint32_t g_anonHostSeq = 0;
+
+}  // namespace
+
+UIHost *UIHost::createHost(const std::string &name) {
+    UIHost *h = UIHost::create();
+    h->meta()->entity = h;
+    if (name.empty()) {
+        h->meta()->name = "host" + std::to_string(++g_anonHostSeq);
+    } else {
+        h->meta()->name = name;
+    }
+    return h;
+}
+
+void UIHost::setName(const std::string &name) { meta()->name = name; }
+
+const std::string &UIHost::getName() { return meta()->name; }
+
+void UIHost::setTree(WidgetDesc root) { applyTree(this, std::move(root)); }
+
+bool UIHost::setTreeReconcile(WidgetDesc root) { return applyTreeReconcile(this, std::move(root)); }
+
+void UIHost::setSimplePanel(const std::string &title, const std::string &labelText,
+                            const std::string &buttonText, const std::string &labelId,
+                            const std::string &buttonId) {
+    setTree(window(title,
+                   {
+                       text(labelText, labelId),
+                       button(buttonText, buttonId),
+                   },
+                   "root"));
+}
+
+UINode *UIHost::findById(const std::string &id) {
+    if (id.empty()) return nullptr;
+    auto t = tree();
+    for (auto &n : t->nodes) {
+        if (n.id == id) return &n;
+    }
+    return nullptr;
+}
+
+UINode *UIHost::findByKey(const std::string &key) {
+    if (key.empty()) return nullptr;
+    auto t = tree();
+    for (auto &n : t->nodes) {
+        if (n.key == key) return &n;
+    }
+    return nullptr;
+}
+
+void UIHost::setTextById(const std::string &id, const std::string &text) {
+    if (auto *n = findById(id)) n->text = text;
+}
+
+void UIHost::setVisibleById(const std::string &id, bool visible) {
+    if (auto *n = findById(id)) n->visible = visible;
+}
+
+void UIHost::setCheckedById(const std::string &id, bool checked) {
+    if (auto *n = findById(id)) n->checked = checked;
+}
+
+void UIHost::setValueById(const std::string &id, float value) {
+    if (auto *n = findById(id)) n->value = value;
+}
+
+void UIHost::setValueTextById(const std::string &id, const std::string &value) {
+    if (auto *n = findById(id)) n->valueText = value;
+}
+
+bool UIHost::setClickHandler(const std::string &id, std::function<void()> fn) {
+    auto *n = findById(id);
+    if (!n) return false;
+    auto t = tree();
+    if (n->handlerClick != 0) {
+        size_t idx = size_t(n->handlerClick - 1);
+        if (idx < t->clickHandlers.size()) {
+            t->clickHandlers[idx] = std::move(fn);
+            return true;
+        }
+    }
+    t->clickHandlers.push_back(std::move(fn));
+    n->handlerClick = static_cast<uint32_t>(t->clickHandlers.size());
+    return true;
+}
+
+bool UIHost::setToggleHandler(const std::string &id, std::function<void(bool)> fn) {
+    auto *n = findById(id);
+    if (!n) return false;
+    auto t = tree();
+    if (n->handlerToggle != 0) {
+        size_t idx = size_t(n->handlerToggle - 1);
+        if (idx < t->toggleHandlers.size()) {
+            t->toggleHandlers[idx] = std::move(fn);
+            return true;
+        }
+    }
+    t->toggleHandlers.push_back(std::move(fn));
+    n->handlerToggle = static_cast<uint32_t>(t->toggleHandlers.size());
+    return true;
+}
+
+bool UIHost::setValueHandler(const std::string &id, std::function<void(float)> fn) {
+    auto *n = findById(id);
+    if (!n) return false;
+    auto t = tree();
+    if (n->handlerValue != 0) {
+        size_t idx = size_t(n->handlerValue - 1);
+        if (idx < t->valueHandlers.size()) {
+            t->valueHandlers[idx] = std::move(fn);
+            return true;
+        }
+    }
+    t->valueHandlers.push_back(std::move(fn));
+    n->handlerValue = static_cast<uint32_t>(t->valueHandlers.size());
+    return true;
+}
+
+bool UIHost::setTextHandler(const std::string &id, std::function<void(const std::string &)> fn) {
+    auto *n = findById(id);
+    if (!n) return false;
+    auto t = tree();
+    if (n->handlerText != 0) {
+        size_t idx = size_t(n->handlerText - 1);
+        if (idx < t->textHandlers.size()) {
+            t->textHandlers[idx] = std::move(fn);
+            return true;
+        }
+    }
+    t->textHandlers.push_back(std::move(fn));
+    n->handlerText = static_cast<uint32_t>(t->textHandlers.size());
+    return true;
+}
+
+}  // namespace eve::ui