Long-context window detection reworked, with new maximum_window and clamp fields

What

The context window is how much text a model can consider at once. Some models can reach 1 million tokens (1M).

• The model schema accepts two new optional fields from remote config: maximum_window and clamp_long_context_without_beta.
• Sonnet 4, Sonnet 4.6 and Opus 4.6 now carry maximum_window: 1e6 (1 million). Sonnet 4 also has clamp_long_context_without_beta set.
• The capability record replaces has1mWithoutOptIn and unclampedButBilledPast200k with longContextWindowWithoutOptIn and apiContextWindowWithoutOptIn.
• The check for whether a window counts as long-context without opt-in now compares it with the larger of those two values instead of testing a fixed size and a yes/no flag.
• The long-context warning and the claude-desktop 1M notice now compare against a threshold instead of reading a yes/no value.

Why

This can change when a model is treated as having more than 200k context without opting in, which affects context limits, compaction and the 1M notice. The limits can now be adjusted from the server.