Implement UI scaling and more (#501)

**New Features**
 * Runtime font accessors and new symbol fonts for text, launcher, statusbar, and shared icons.
 * Added font height base setting to device.properties
 * Text fonts now have 3 sizes: small, default, large

**Improvements**
 * Renamed `UiScale` to `UiDensity`
 * Statusbar, toolbar and many UI components now compute heights and spacing from fonts/density.
 * SSD1306 initialization sequence refined for more stable startup.
 * Multiple image assets replaced by symbol-font rendering.
 * Many layout improvements related to density, font scaling and icon scaling
 * Updated folder name capitalization for newer style

TactilityKernel/source/log.cpp

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#ifndef ESP_PLATFORM
+
+#include <tactility/log.h>
+
+#include <mutex>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include <sys/time.h>
+
+static const char* get_log_color(LogLevel level) {
+    using enum LogLevel;
+    switch (level) {
+        case LOG_LEVEL_ERROR:
+            return "\033[1;31m";
+        case LOG_LEVEL_WARNING:
+            return "\033[1;33m";
+        case LOG_LEVEL_INFO:
+            return "\033[32m";
+        case LOG_LEVEL_DEBUG:
+            return "\033[36m";
+        case LOG_LEVEL_VERBOSE:
+            return "\033[37m";
+        default:
+            return "";
+    }
+}
+
+static inline char get_log_prefix(LogLevel level) {
+    using enum LogLevel;
+    switch (level) {
+        case LOG_LEVEL_ERROR:
+            return 'E';
+        case LOG_LEVEL_WARNING:
+            return 'W';
+        case LOG_LEVEL_INFO:
+            return 'I';
+        case LOG_LEVEL_DEBUG:
+            return 'D';
+        case LOG_LEVEL_VERBOSE:
+            return 'V';
+        default:
+            return '?';
+    }
+}
+
+static uint64_t get_log_timestamp() {
+    static uint64_t base = 0U;
+    static std::once_flag init_flag;
+    std::call_once(init_flag, []() {
+      timeval time {};
+      gettimeofday(&time, nullptr);
+      base = ((uint64_t)time.tv_sec * 1000U) + (time.tv_usec / 1000U);
+    });
+    timeval time {};
+    gettimeofday(&time, nullptr);
+    uint64_t now = ((uint64_t)time.tv_sec * 1000U) + (time.tv_usec / 1000U);
+    return now - base;
+}
+
+extern "C" {
+
+void log_generic(enum LogLevel level, const char* tag, const char* format, ...) {
+    va_list args;
+    va_start(args, format);
+    printf("%s %c (%" PRIu64 ") %s ", get_log_color(level), get_log_prefix(level), get_log_timestamp(), tag);
+    vprintf(format, args);
+    printf("\033[0m\n");
+    va_end(args);
+}
+
+}
+
+#endif