Add Kiro Claude Opus 5, correct Opus 4.6 output limit, and document absent reasoning controls

[NachoFLizaur]

Summary

• Adds the Kiro Claude Opus 5 provider entry from the existing immutable commit.
• Corrects the Kiro Claude Opus 4.6 output limit to 64K.
• Adds comment-only documentation to five Kiro model files explaining their absent reasoning controls.
• Keeps the Kiro catalog at 19 models.
• Leaves Qwen3-Coder-Next source unchanged.

Qwen deferral

Existing inline Qwen3-Coder-Next metadata is intentionally unchanged because creating the missing Alibaba canonical is separate catalog work; migrate Kiro to base_model if/when that canonical lands.

Kiro runtime evidence

• Captured output limits are 64K for Claude Opus 4.6 and 128K for Claude Opus 4.7, 4.8, and 5. Opus 4.6 now has the 64K provider override.
• The authenticated Kiro ACP capture returned exact empty /effort option lists for Claude Haiku 4.5, Claude Opus 4.5, Claude Sonnet 4, Claude Sonnet 4.5, and GLM-5. Their explicit reasoning_options = [] arrays are preserved, and per the review request each of the five files now carries a top-of-file source comment citing both the supported-model effort table omission and the source from the docs.
• Claude Opus 5 effort remains low, medium, high, xhigh, max.