fix(opencode): refresh Go catalog and accept terminal pings

[Aser-Osama]

OpenCode Go's live catalog includes models that the proxy does not yet recognize, so Claude Code rejects those model IDs before reaching the provider. This refreshes the catalog with the 14 missing models and their Chat Completions, Messages, or Responses routes. It also keeps grok-4.6 provider-qualified so the bare ID remains owned by the native Grok provider, and extends GLM reasoning-effort handling to GLM 5.3.

Live testing exposed a second issue on the newly routed opencode-go/grok-4.6: OpenCode appends a billing ping after response.completed, which made both buffered and streaming translation fail with HTTP 502. The translator now ignores only that harmless trailing ping while continuing to reject duplicate terminal events, late content, and malformed trailing frames.

Added models:

• grok-4.6, glm-5.3, glm-5.3-flash, longcat-2.0
• deepseek-flash, deepseek-v4-flash-vision-exp
• mimo-v2-pro, mimo-v2-omni
• qwen3.8-flash, hy4-preview, hy3-preview
• muse-spark-1.3-contributor, muse-spark-1.2-contributor, omen-alpha

Validation:

• cargo test — all unit, integration, and smoke suites pass
• Live GLM 5.3 Flash request through the proxy — HTTP 200
• Live Qwen 3.8 Flash request through the proxy — HTTP 200
• Live Grok 4.6 buffered and streaming requests through the proxy — HTTP 200 with clean completion

[raine]

Thank you