Union Alpha is OpenRouter's new $0 stealth model (262,144 ctx, tools +
tool_choice supported, text+image in). It carries no ":free" suffix, so it
needs an explicit "free, stealth model" description and an _OPENROUTER_ONLY
entry to keep it out of the derived Nous Portal list, plus a "union-alpha"
DEFAULT_CONTEXT_LENGTHS key so the offline resolver returns 262144 instead
of the 256K catch-all. Docs manifest regenerated in the same commit.
Live gate: max_tokens=64 tool-calling completion on origin/main key returned
200, echoed model stealth/union-alpha, usage.cost=0, finish_reason=tool_calls.
d0aecdf352