[henrychu04]

The fork now uses upstream's runtime-mode handling. One small difference remains: a mode the workspace policy disallows steps down to the next lower allowed mode, where upstream drops to Supervised.

Why: the Fable review of the 67661cf → 6d450a4 sync found that pingdotgg#25869's new-thread permissions label used upstream's resolver while the composer used the fork's. The label could say "Full access" while the run got "Auto-accept edits". Rather than add another seam, this removes the fork's own mode logic.

Changes:

• Provider-level modes. Claude (its disableAutoMode and disableBypassPermissionsMode policy) and Codex (configRequirements/read) report allowed modes through upstream's provider-level supportedRuntimeModes. If the policy can't be read, they offer only the safe modes.
• Removed fork code:
  • per-model supportedRuntimeModes and CustomModelCapabilities (contracts and shared go back to upstream);
  • attachSupportedRuntimeModes;
  • the composer's resolveComposerRuntimeModes and its safe-modes-until-ready rule;
  • RuntimePolicy.modelRuntimeMode;
  • their fork-only tests.
• One shared mode list. The composer, the new-thread label, RuntimePolicy and delegated tasks all read it with upstream's code.
• Step-down rule. runtimeModeConfig.resolveCompatibleRuntimeMode and RuntimePolicy.providerRuntimeMode both step an unsupported mode down to the broadest offered mode below it, as upstream's delegatedTaskModes.resolveRuntimeMode already does. This is the only remaining delta, marked Coder: in both places.
• Docs. docs/user/permission-modes.md describes the policy, the step-down, and the new-thread default setting. coder-only.md is updated.

Trade-off: while a provider is still probing, the composer shows all four modes. Once the policy is read, the list and the mode the run gets are correct.

Verification:

• pnpm test:coder passes, except the known localApi load flake (Tests that flake under full-suite load #236), which passes alone.
• pnpm build passes.
• The typechecks for server, web, helper, contracts, shared, client-runtime, coder-cli and the provider packages pass.
• pnpm knip:check, pnpm test:knip, vp fmt --check and the unused-locals check pass.
• A throwaway test covered the step-down: Full access → Auto, Auto → Auto-accept edits, a mode below every allowed one → the lowest allowed, and no policy keeps the choice.
• Not checked live: real Claude and Codex need quota in the harness workspaces. Upstream's own RuntimePolicy test passes unchanged.

🤖 Generated with Claude Code