Abhinav 8228e9b867 Resolve token budgets from each step's active model (#41162) ...

## Why

Model settings can change between steps in the same turn. Token-budget defaults,
context-window limits, and model-visible guidance need to stay aligned with the
model captured for each step.

## What changed

- Preserve the turn's original token-budget preferences and resolve model-owned
  defaults when each `StepContext` is created.
- Use the step's model to determine context-window availability and token-budget
  guidance, while keeping explicit user settings unchanged.
- Emit one-time replacement or removal notices when context-window guidance
  changes, including compatibility with previously persisted world-state
  snapshots.
- Add `ModelInfo::usable_context_window()` to distinguish reserved-headroom
  capacity from the resolved context window and auto-compaction limit.

## Testing

- Cover mid-turn model switches with model defaults, explicit settings, config
  reloads, missing context windows, and missing destination guidance.
- Cover unchanged, replaced, removed, blank, and legacy guidance transitions.

GitOrigin-RevId: 91100a9f3625bef8a79ecd158eb028051c309eee

2026-08-27 15:01:22 +00:00

..

common

Support standalone function outputs in turn routing (#40991)

2026-08-26 22:48:37 +00:00

remote_env_windows

Standardize shell execution on unified exec (#39772)

2026-08-20 18:29:35 +00:00

suite

Resolve token budgets from each step's active model (#41162)

2026-08-27 15:01:22 +00:00

all.rs

[codex] Use expect in integration tests (#28441)

2026-06-15 21:53:47 -07:00

responses_headers.rs

Sanitize credentials from Git remote metadata (#40713)

2026-08-25 21:34:05 +00:00