v0.12.161

• De-Gemini the Anthropic-primary fallback chains. When Anthropic hiccups (503s, capacity), Gemini's own "high demand" 503s correlate with the same events — agents fall back from Claude to Gemini together, both overloaded. Reordered src/router/config.ts fallback arrays in the two places Anthropic sits primary: premiumTiers.COMPLEX (claude-opus-4.7 primary) and agenticTiers.COMPLEX (claude-sonnet-4.6 primary). New order: in-family Anthropic hot swap (opus-4.6 / sonnet-4.6) → xAI Grok (independent infra, strong on complex + tool use) → Moonshot Kimi K2.6 / K2.5 (separate Moonshot infra) → OpenAI flagship (slow but reliable) → DeepSeek (cheap reliable) → free/qwen3-coder-480b (NVIDIA free ultimate backstop). Gemini removed entirely from both chains. Other Anthropic-primary tiers (premiumTiers.REASONING, agenticTiers.REASONING) already had no Gemini and were not touched.