WA multibyte alphabets render but never commit output (no text produced when steering) #70

What

Every WorldAlphabets alphabet with multi-byte symbols (Arabic, Hebrew, Amharic, Urdu, …) renders a weighted tree after the colour-token fix (da2e558) but produces no output when steered — dasher_get_output_text stays empty forever. WA ASCII alphabets (English) output fine; legacy v5 multibyte alphabets (Russian) output fine.

Evidence (engine-level probes, no fonts involved)

Identical steering program (fixed coordinates, hold, 100–1000 frames, turbo constant-time convention that reliably yields output for other alphabets):

• engineError stays 0; no log messages; no crash.
• CDasherModel::GetOffset() shows m_pLastOutput set (root path) but never advances — OutputTo(node) never receives an unseen node, so Do()/actions never run.
• Not geometry: swept x∈{40,100,700,760} and y∈{100..500} — no coordinate commits.
• Not RTL: Amharic (LTR) fails identically.

Pre-existing, not a #68 regression

Reproduced on pre-PR main (901e4d8, eager parsing) with the colour-fixed data — zero output there too. Nobody could see this before because these alphabets rendered invisible (#69 colour tokens) until da2e558.

Suspects

• The distinguishing parse shape is WA node elements whose multi-byte label becomes both Display and Text (no text attr), combined with duplicate symbols (Hebrew: 27, Arabic: 36, Amharic: 282 — every WA multibyte file has dups; WA English has none). The commit path (Reparent_root/Render→OutputTo) appears to depend on something the duplicate/multibyte map breaks — likely interaction with CAlphabetMap lookups during root rebuild (RebuildFindFromOffset text→symbol round-trip).
• Probe binaries and methodology available; DODUMP instrumentation point: CSymbolNode::Do() in AlphabetManager.cpp.

Impact

All WA-served RTL/Indic/Ethiopic/… languages are view-but-cannot-write. Combined with the 148-of-474 missing training corpora, the WA usability tail is: render ✓ (fixed), train (148 missing corpora), write ✗ (this issue).