feat(extensions): polish app install UX

src/activities/apps/AppsActivity.cpp

@@ -86,9 +86,12 @@ void AppsActivity::launchApp() {
   
   CrossPoint::AppLoader loader;
   bool success = loader.flashApp(binPath, [this](size_t written, size_t total) {
-    flashProgress_ = static_cast<int>((written * 100) / total);
-    needsUpdate_ = true;
-    renderProgress();
+    const int nextProgress = (total > 0) ? static_cast<int>((written * 100) / total) : 0;
+    if (nextProgress != flashProgress_) {
+      flashProgress_ = nextProgress;
+      needsUpdate_ = true;
+      renderProgress();
+    }
   });
   
   if (!success) {
@@ -134,7 +137,8 @@ void AppsActivity::render() {
         int textWidth = renderer_.getTextWidth(UI_12_FONT_ID, buf);
         int x = (pageWidth - textWidth) / 2 - 10;
         renderer_.fillRect(x, y - 5, textWidth + 20, lineHeight - 5);
-        renderer_.drawText(UI_12_FONT_ID, x + 10, y, buf, true);  // inverted
+        // Draw white text on black highlight.
+        renderer_.drawText(UI_12_FONT_ID, x + 10, y, buf, false);
       } else {
         renderer_.drawCenteredText(UI_10_FONT_ID, y, buf);
       }

src/activities/home/HomeActivity.cpp

@@ -506,7 +506,8 @@ void HomeActivity::render() {
 
   // --- Bottom menu tiles ---
   // Build menu items dynamically
-  std::vector<const char*> menuItems = {"My Library", "File Transfer", "Settings"};
+  // Keep this list in sync with getMenuItemCount() and loop() index mapping.
+  std::vector<const char*> menuItems = {"My Library", "File Transfer", "Apps", "Settings"};
   if (hasOpdsUrl) {
     // Insert OPDS Browser after My Library
     menuItems.insert(menuItems.begin() + 1, "OPDS Browser");

src/apps/hello-world/HelloWorldActivity.cpp

@@ -19,7 +19,7 @@ EpdFont ui12BoldFont(&ubuntu_12_bold);
 EpdFontFamily ui12FontFamily(&ui12RegularFont, &ui12BoldFont);
 }
 
-HelloWorldActivity::HelloWorldActivity(EInkDisplay& display, InputManager& input)
+HelloWorldActivity::HelloWorldActivity(HalDisplay& display, HalGPIO& input)
     : display_(display), input_(input), needsUpdate_(true) {}
 
 void HelloWorldActivity::onEnter() {
@@ -35,7 +35,7 @@ void HelloWorldActivity::onEnter() {
 }
 
 void HelloWorldActivity::loop() {
-  if (input_.wasPressed(InputManager::BTN_BACK)) {
+  if (input_.wasPressed(HalGPIO::BTN_BACK)) {
     returnToLauncher();
     return;
   }

src/apps/hello-world/HelloWorldActivity.h

@@ -1,19 +1,19 @@
 #pragma once
 
-#include <EInkDisplay.h>
-#include <InputManager.h>
+#include <HalDisplay.h>
+#include <HalGPIO.h>
 
 class HelloWorldActivity {
  public:
-  HelloWorldActivity(EInkDisplay& display, InputManager& input);
+  HelloWorldActivity(HalDisplay& display, HalGPIO& input);
   
   void onEnter();
   void loop();
   void onExit();
   
  private:
-  EInkDisplay& display_;
-  InputManager& input_;
+  HalDisplay& display_;
+  HalGPIO& input_;
   bool needsUpdate_;
   
   void render();

src/apps/hello-world/main.cpp

@@ -1,32 +1,31 @@
 #include <Arduino.h>
-#include <EInkDisplay.h>
-#include <InputManager.h>
+#include <HalDisplay.h>
+#include <HalGPIO.h>
+
 #include "HelloWorldActivity.h"
 
-// Display SPI pins for Xteink X4
-#define EPD_SCLK 8
-#define EPD_MOSI 10
-#define EPD_CS 21
-#define EPD_DC 4
-#define EPD_RST 5
-#define EPD_BUSY 6
-
-EInkDisplay display(EPD_SCLK, EPD_MOSI, EPD_CS, EPD_DC, EPD_RST, EPD_BUSY);
-InputManager input;
-HelloWorldActivity activity(display, input);
+HalDisplay display;
+HalGPIO gpio;
+HelloWorldActivity activity(display, gpio);
 
 void setup() {
-  Serial.begin(115200);
-  Serial.println("[HelloWorld] Starting...");
-  
-  input.begin();
+  gpio.begin();
+
+  // Only start serial if USB connected
+  if (gpio.isUsbConnected()) {
+    Serial.begin(115200);
+    Serial.println("[HelloWorld] Starting...");
+  }
+
   activity.onEnter();
-  
-  Serial.println("[HelloWorld] Activity started");
+
+  if (Serial) {
+    Serial.println("[HelloWorld] Activity started");
+  }
 }
 
 void loop() {
-  input.update();
+  gpio.update();
   activity.loop();
   delay(10);
 }

src/extension/AppLoader.cpp

@@ -102,8 +102,15 @@ AppManifest AppLoader::parseManifest(const String& path) {
     return manifest;
   }
 
+  // Handle UTF-8 BOM if the manifest was created by an editor that writes it.
+  const char* json = buffer.get();
+  if (bytesRead >= 3 && static_cast<uint8_t>(json[0]) == 0xEF && static_cast<uint8_t>(json[1]) == 0xBB &&
+      static_cast<uint8_t>(json[2]) == 0xBF) {
+    json += 3;
+  }
+
   JsonDocument doc;
-  const DeserializationError error = deserializeJson(doc, buffer.get());
+  const DeserializationError error = deserializeJson(doc, json);
 
   if (error) {
     Serial.printf("[%lu] [AppLoader] JSON parse error in %s: %s\n",
@@ -230,12 +237,16 @@ bool AppLoader::flashApp(const String& binPath, ProgressCallback callback) {
   }
 
   if (callback) {
-    callback(0, 100);
+    callback(0, fileSize);
   }
 
   size_t totalWritten = 0;
-  static constexpr size_t flashChunkSize = 1024;
-  uint8_t buffer[flashChunkSize];
+  // Larger chunks reduce SD/OTA overhead significantly.
+  // 32KB is a good balance on ESP32-C3: faster writes without blowing RAM.
+  static constexpr size_t flashChunkSize = 32 * 1024;
+  static uint8_t buffer[flashChunkSize];
+
+  size_t lastNotifiedPercent = 0;
 
   while (totalWritten < fileSize) {
     const size_t remaining = fileSize - totalWritten;
@@ -260,7 +271,11 @@ bool AppLoader::flashApp(const String& binPath, ProgressCallback callback) {
 
     if (callback) {
       const size_t percent = (totalWritten * 100) / fileSize;
-      callback(percent, 100);
+      // Throttle UI updates; each screen refresh is ~400ms.
+      if (percent >= lastNotifiedPercent + 10 || percent == 100) {
+        lastNotifiedPercent = percent;
+        callback(totalWritten, fileSize);
+      }
     }
   }