refactor: capitalize app directory names

The directory name is what the status bar and the launcher cards display, so Home,
Hello and Settings read as titles without a lookup table. Updates the firmware's home
path, the launcher's self-exclusion and the host tests that load the settings app.

Also brings the bar's next repaint forward when an app renames itself or the frame
rotates. The bar still decides what changed; this only stops the answer waiting most of
a second for the next tick.

src/main.cpp

@@ -15,7 +15,7 @@ static constexpr int SD_MOSI = 23;
 static constexpr int SD_MISO = 19;
 static constexpr int TOUCH_CS = 33;
 
-static const char* HOME = "/apps/home/main.lua";
+static const char* HOME = "/apps/Home/main.lua";
 static constexpr uint32_t ERROR_HOLD_MS = 5000;
 
 // Arduino's default 8KB loop stack is not enough once a TLS handshake runs inside a
@@ -45,7 +45,7 @@ void fallbackScreen(const char* message) {
   tft.setTextColor(TFT_RED, TFT_WHITE);
   tft.drawString(message, 10, 10);
   tft.setTextColor(TFT_BLACK, TFT_WHITE);
-  tft.drawString("expected /apps/home/main.lua", 10, 30);
+  tft.drawString("expected /apps/Home/main.lua", 10, 30);
   Serial.printf("halted: %s\n", message);
   halted = true;
 }