docs(wasm-dom): Phase 6 — feature README, divergence audit, patches

Fork delta vs wasm-port: 8 commits, ~107 files — port directory, 35
dispatch headers, build-system entries, 1-line prntbase.cpp condition,
2 generic-notebook bug fixes. No univ/aui/stc changes. Tracker-hook
migration deliberately deferred while the canvas port is alive (the DOM
port doesn't need the hooks; univ's die with univ). Patches in
features/feature/wx-dom-port/ via create-feature-patches.sh.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/features/wx-dom-port/README.md

@@ -0,0 +1,92 @@
+# wxWidgets DOM port (`feature/wx-dom-port`)
+
+A second WASM build mode where wxWidgets widgets are **real HTML elements**
+(`wxButton` → `<button>`, `wxTextCtrl` → `<input>`, menus → popup divs)
+instead of wxUniversal pixels on a canvas. Goals: styleable modern UI,
+native text input/IME, accessibility, crisp rendering — while the existing
+canvas port keeps working unchanged from the same source tree.
+
+Status: wxWidgets-side port complete (Phases 0–5); both e2e suites green
+from one tree. KiCad-on-DOM is the next phase. Work intentionally stays on
+`feature/wx-dom-port` (root + wxwidgets + kicad) — not merged to
+`main`/`wasm-port`.
+
+## Architecture in one page
+
+- **One toolkit, two modes.** `--with-wasm --enable-universal` = canvas
+  (untouched); `--with-wasm` alone = DOM. Selection is file-level via the
+  build system: `src/univ/` only in canvas builds, `WASM_SRC` (native
+  controls) only under `WXUNIV_0`. Source of truth is
+  `build/bakefiles/files.bkl` → dockerized bakefile regenerates
+  `Makefile.in`/`autoconf_inc.m4` → autoconf regenerates `configure`
+  (`scripts/build-wxuniversal-wasm.sh` auto-detects each stage's
+  staleness; `--dom` flag selects the mode).
+- **C++ owns state; the DOM is a projection.** Controls call
+  `WasmCreateDomNode("type")` once in `Create()`; the shared
+  `wxWindowWasm` machinery then syncs geometry (TLW-relative absolute
+  positioning, recursing into descendants), visibility
+  (`IsShownOnScreen`, whole subtree), enabled/font/focus/destruction.
+  DOM-native state (typed text, checked, selection) syncs back through
+  events into C++ caches so getters stay synchronous.
+- **Layout is wx sizers, not CSS.** DOM contributes intrinsic measurement
+  only (clone-based, in an offscreen always-rendered host — sizers run
+  before `Show()`); positions are written as absolute `left/top/w/h`.
+- **Events** flow element listener → `ccall('wx_dom_event')` →
+  `domevents.cpp` routing table → virtual `wxWindowWasm::OnDomEvent` —
+  the same direct-dispatch pattern as the port's mouse callbacks (proven
+  against Asyncify-suspended modals). Keyboard arbitration: keystrokes go
+  untouched to focused DOM editables (Escape excepted).
+- **Canvas islands.** Owner-drawn/generic widgets (wxGrid, listctrl,
+  tree, AUI, STC, calendar...) keep painting via the shared `dc.cpp`
+  Canvas2D path inside per-window canvases; they render near-pixel-equal
+  to the canvas port.
+- **Menus/toolbars** serialize C++→JS as JSON; popups are DOM divs;
+  command ids route back via `wxDOM_EVENT_MENU`/`TOOL`. Menu titles,
+  items, and tools register as rendered elements with the same
+  type strings the canvas port uses, so registry-based e2e utilities work
+  identically on both ports.
+
+Key files: `wxwidgets/build/wasm/wx-dom.js` (the whole JS control layer),
+`wxwidgets/include/wx/wasm/private/dom.h` (C++→JS bridge),
+`wxwidgets/src/wasm/domevents.cpp` (event routing + bitmap data URLs),
+`wxwidgets/src/wasm/window.cpp` (DOM-backing machinery, guarded
+`#ifndef __WXUNIVERSAL__`).
+
+## What works (e2e-verified, WX_PORT=dom)
+
+Full `tests/e2e` suite green (256/0; canvas 263/0 from the same tree, its
+stable screenshot set byte-identical to the pre-feature reference).
+
+- Native DOM: stattext, button (stock labels, default size), textctrl
+  (single/multi/password, two-way sync, wxEVT_TEXT/_ENTER), checkbox,
+  radiobutton (HTML name groups from wxRB_GROUP chains), radiobox,
+  togglebutton, gauge, slider, statline, statbox, statbmp (PNG data
+  URLs), bitmap buttons, choice, listbox, editable combobox
+  (input+datalist), checklistbox, spinbutton (drives generic wxSpinCtrl),
+  menubar+menus, toolbar, tooltips (title attrs), dialogs (shared
+  Asyncify ShowModal), frame bar geometry (univ-parity).
+- Canvas islands verified visually: AUI, calendar, virtual listctrl,
+  grid, tree, propgrid, STC.
+
+## Known gaps / polish (tracked in visual-notes.md)
+
+- wxSpinCtrl text field collapses beside the spin pair (generic composite
+  sizing); bitmap-button vertical centering; checklistbox selection
+  highlight; wxLB_SINGLE uses a multiple `<select>`; native scrollbars
+  replace univ gutters.
+- Tracker hooks in `src/generic/`+aui/stc/propgrid are shared with the
+  canvas port and stay until the canvas port retires (the DOM port itself
+  doesn't need them — its controls register from creation + ARIA). The
+  univ hooks die with univ automatically.
+
+## Upstreaming surface (vs `wasm-port` base)
+
+8 commits, ~107 files: the port directory itself (new files), 35
+dispatch-header branches (2–4 lines each), build-system entries
+(bakefile-generated), one-line `prntbase.cpp` PostScript condition, and
+two genuine upstream bug fixes in the generic notebook
+(`tabg.cpp` uninitialized background brush; `notebook.cpp` first-page
+selection never syncing the tab view). Zero changes to univ/aui/stc.
+
+See `visual-notes.md` for the 15-bug log the cross-port screenshot
+comparison protocol produced.

wxwidgets

@@ -1 +1 @@
-Subproject commit 5de7b0f072d2dd26c83347190d0587121a9df39e
+Subproject commit 34aa940aa7c1f9d82d03ec5fe50df16374a32670