Phase 2 of M135→M147 catch-up (fathyb#33, fathyb#35). All 24 carbonyl patches
rebased from M140 to M147 (147.0.7727.94).

Patch conflicts resolved (11):
- 0001: headless/BUILD.gn — kept both M147 deps + carbonyl dep
- 0002: font.cc, render_frame_impl.h, render_frame_host_impl.h —
  kept carbonyl Mojo members + M147 BrokerHolder struct
- 0003: host_display_client.h, viz_process_transport_factory.cc —
  kept LayeredWindowUpdater + M147 IS_MAC includes
- 0005: paint_artifact_compositor.cc — removed debug dump calls
- 0006: headless_screen.cc — carbonyl bridge include + DPI scaling
- 0007: text_decoration_painter.cc — disabled underline/overline
- 0009: headless_web_contents_impl.cc, headless_browser_impl.h —
  merged includes + carbonyl input methods
- 0010: render_frame_impl.cc — merged M147 perfetto + carbonyl Skia
- 0013: 6 files — merged includes and deps
- 0023: headless_browser_impl.cc — merged includes
- 0024: blink/renderer/platform/BUILD.gn — carbonyl visibility

Build fixes for M147 API drift:
- args.gn: use_dbus=true (wayland ozone now requires clipboard_util_linux)
- headless/BUILD.gn: removed phantom //carbonyl/src/browser:carbonyl dep
- renderer.cc: replaced static unique_ptr with leaked raw pointer
  (-Wexit-time-destructors)
- text_capture.cc: drawPath(bool=false) → drawPath(2-arg);
  getRelativeTransform returns SkM44 (use .asM33());
  static RendererService → leaked pointer
- host_display_client.h: ui/gfx/native_widget_types.h → native_ui_types.h;
  added SkBitmap.h include; viz target deps += //ui/gfx
- host_display_client.cc: removed obsolete resource_sizes.h include
- software_output_device_proxy.cc: ResourceSizes::MaybeSizeInBytes →
  SharedImageFormat::MaybeEstimatedSizeInBytes
- browser_interface_binders.cc: Mojo BinderMap::Add signature changed;
  use BindRenderFrameHostImpl<...> template
- headless_browser_impl.cc: added navigation_controller.h include;
  PlatformSetWebContentsBounds → SetWebContentsBounds
- headless_screen.cc: removed duplicate ~HeadlessScreen() = default
- headless_web_contents_impl.h: using WebContentsObserver::OnVisibilityChanged
- text_decoration_painter.cc: (void)skip_ink suppression
- paint_artifact_compositor.cc: removed orphan debug dump function
- font.{h,cc}: removed dead Font::DrawText(TextRun) overloads
  (CachingWordShaper/ShapeResultBuffer removed in M147)

Also: added project sponsors section to readme.md.

Verified: ninja 2775/2775, smoke test 3/3 (ItemDelta replaces Foxtrot
for M147 viewport size).

Refs fathyb#35

- Add M140→M147 upgrade section with 11 conflict resolutions and 20
  build fixes documented
- Update readme: M140 → M147, phases 5 → 6, current upstream stable
- Update MAINTENANCE: version string, base commits, patch notes for
  M147 API drift, GN args header

Refs fathyb#33, fathyb#35