feat: donation banner, About tab, settings UI improvements

- Dismissible donation/open-source banner after 3+ sessions (30-day snooze)
- New About tab in Settings: version, repo link, license info
- Centralize project URLs (REPO_URL, DONATE_URL) in __init__.py, served via /health
- Center settings tab bar, reduce tab padding for 6-tab fit
- External URL save button: icon button instead of full-width text button
- Remove redundant settings footer close button
- Footer "Source Code" link replaced with "About" opening settings
- i18n keys for en/ru/zh

server/src/wled_controller/api/routes/system.py

@@ -13,7 +13,7 @@ from typing import Optional
 import psutil
 from fastapi import APIRouter, Depends, HTTPException, Query
 
-from wled_controller import __version__
+from wled_controller import __version__, REPO_URL, DONATE_URL
 from wled_controller.api.auth import AuthRequired, is_auth_enabled
 from wled_controller.api.dependencies import (
     get_audio_source_store,
@@ -54,7 +54,11 @@ logger = get_logger(__name__)
 psutil.cpu_percent(interval=None)
 
 # GPU monitoring (initialized once in utils.gpu, shared with metrics_history)
-from wled_controller.utils.gpu import nvml_available as _nvml_available, nvml as _nvml, nvml_handle as _nvml_handle  # noqa: E402
+from wled_controller.utils.gpu import (  # noqa: E402
+    nvml_available as _nvml_available,
+    nvml as _nvml,
+    nvml_handle as _nvml_handle,
+)
 
 
 def _get_cpu_name() -> str | None:
@@ -77,9 +81,7 @@ def _get_cpu_name() -> str | None:
                         return line.split(":")[1].strip()
         elif platform.system() == "Darwin":
             return (
-                subprocess.check_output(
-                    ["sysctl", "-n", "machdep.cpu.brand_string"]
-                )
+                subprocess.check_output(["sysctl", "-n", "machdep.cpu.brand_string"])
                 .decode()
                 .strip()
             )
@@ -107,6 +109,8 @@ async def health_check():
         version=__version__,
         demo_mode=get_config().demo,
         auth_required=is_auth_enabled(),
+        repo_url=REPO_URL,
+        donate_url=DONATE_URL,
     )
 
 
@@ -131,12 +135,22 @@ async def list_all_tags(_: AuthRequired):
     """Get all tags used across all entities."""
     all_tags: set[str] = set()
     from wled_controller.api.dependencies import get_asset_store
+
     store_getters = [
-        get_device_store, get_output_target_store, get_color_strip_store,
-        get_picture_source_store, get_audio_source_store, get_value_source_store,
-        get_sync_clock_store, get_automation_store, get_scene_preset_store,
-        get_template_store, get_audio_template_store, get_pp_template_store,
-        get_pattern_template_store, get_asset_store,
+        get_device_store,
+        get_output_target_store,
+        get_color_strip_store,
+        get_picture_source_store,
+        get_audio_source_store,
+        get_value_source_store,
+        get_sync_clock_store,
+        get_automation_store,
+        get_scene_preset_store,
+        get_template_store,
+        get_audio_template_store,
+        get_pp_template_store,
+        get_pattern_template_store,
+        get_asset_store,
     ]
     for getter in store_getters:
         try:
@@ -209,15 +223,11 @@ async def get_displays(
     except EntityNotFoundError as e:
         raise HTTPException(status_code=404, detail=str(e))
 
-
     except ValueError as e:
         raise HTTPException(status_code=400, detail=str(e))
     except Exception as e:
         logger.error("Failed to get displays: %s", e, exc_info=True)
-        raise HTTPException(
-            status_code=500,
-            detail="Internal server error"
-        )
+        raise HTTPException(status_code=500, detail="Internal server error")
 
 
 @router.get("/api/v1/system/processes", response_model=ProcessListResponse, tags=["Config"])
@@ -235,10 +245,7 @@ async def get_running_processes(_: AuthRequired):
         return ProcessListResponse(processes=sorted_procs, count=len(sorted_procs))
     except Exception as e:
         logger.error("Failed to get processes: %s", e, exc_info=True)
-        raise HTTPException(
-            status_code=500,
-            detail="Internal server error"
-        )
+        raise HTTPException(status_code=500, detail="Internal server error")
 
 
 @router.get(
@@ -260,9 +267,7 @@ def get_system_performance(_: AuthRequired):
         try:
             util = _nvml.nvmlDeviceGetUtilizationRates(_nvml_handle)
             mem_info = _nvml.nvmlDeviceGetMemoryInfo(_nvml_handle)
-            temp = _nvml.nvmlDeviceGetTemperature(
-                _nvml_handle, _nvml.NVML_TEMPERATURE_GPU
-            )
+            temp = _nvml.nvmlDeviceGetTemperature(_nvml_handle, _nvml.NVML_TEMPERATURE_GPU)
             gpu = GpuInfo(
                 name=_nvml.nvmlDeviceGetName(_nvml_handle),
                 utilization=float(util.gpu),