fix(server): treat tailscale-serve backend as remote-reachable

[caddydove]

Fix #4462

When --tailscale-serve is enabled, the backend is reachable via Tailscale Serve HTTPS URL even though the HTTP server binds to 127.0.0.1.

Adds config.tailscaleServeEnabled to the isRemoteReachable check in EnvironmentAuthPolicy so the auth policy reflects remote reachability, enabling remote pairing and authorized-client controls.

Changes

• apps/server/src/auth/EnvironmentAuthPolicy.ts: Added config.tailscaleServeEnabled || to isRemoteReachable
• apps/server/src/auth/EnvironmentAuthPolicy.test.ts: Added test for loopback host + tailscale-serve combination

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Note

Medium Risk
Auth policy changes affect remote pairing and bootstrap for Tailscale Serve; Claude permission mapping changes tool-approval behavior for auto and approval-required modes.

Overview
Tailscale Serve on loopback is now treated as remote-reachable for auth: EnvironmentAuthPolicy includes config.tailscaleServeEnabled in isRemoteReachable, so a web server bound to 127.0.0.1 with --tailscale-serve gets the remote-reachable policy and one-time-token bootstrap instead of loopback-browser. A test covers loopback + tailscaleServeEnabled.

Claude agent sessions map auto and approval-required runtime modes to the SDK’s default permission mode (replacing auto for the former and making the latter explicit). Tests in ClaudeAdapter.test.ts expect permissionMode: "default" for those modes.

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Note

Treat tailscale-serve backend as remote-reachable in EnvironmentAuthPolicy

• EnvironmentAuthPolicy.make now sets isRemoteReachable to true when tailscaleServeEnabled is set, even if the host is a loopback address, resulting in policy remote-reachable with bootstrapMethods: ['one-time-token'].
• makeClaudeAdapter changes the runtimeMode → permissionMode mapping: 'auto' now maps to 'default' (was 'auto'), and 'approval-required' now maps to 'default' (was undefined).
• Behavioral Change: Sessions with runtimeMode 'auto' or 'approval-required' will send permissionMode: 'default' to Claude instead of 'auto' or omitting the field.

^{Macroscope summarized 1cc3020.}

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[macroscopeapp]

Approvability

Verdict: Needs human review

This PR modifies auth policy behavior and permission mode mapping, both runtime-affecting changes. Additionally, there is an unresolved high-severity review comment flagging that the auto→default mapping may break the expected auto mode behavior, which warrants human review.

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[cursor]

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[cursor]

Auto runtime maps to default

High Severity

Mapping runtimeMode auto to permissionMode default (which is also used for approval-required) drops Claude Code's distinct auto mode. Claude Auto sessions now prompt for approval like 'Approve' actions, breaking the shared auto runtime mode contract.

 

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