fix(sandbox): match Modal region pins through the openrouter/ routing prefix

[devin-ai-integration]

TL;DR

resolveModalRegions now strips the openrouter/ routing prefix before matching MODAL_REGION_PINS, so openrouter/sakana/fugu-ultra lands in a US sandbox like sakana/fugu-ultra does.

What changed?

• New src/harness/model-slug.ts with stripRoutingPrefix, the logic previously inlined in agent-cli/runner.ts#normalizeAgentModel. normalizeAgentModel is now an alias of it, so existing importers are unaffected.
• resolveModalRegions matches pins against the stripped slug.
• Regression tests for the prefixed Fugu slug and for the helper (openrouter/auto stays intact).

Why?

Follow-up to #92. Region selection ran against the raw config model while the agent env ran against the normalized one, so a run configured with the routing-prefixed slug got default placement and the provider 403 the pin exists to avoid. Flagged by Devin Review on openrouter-web#44769.

How to test

bun test src/sandbox/modal-regions.test.ts src/harness/model-slug.test.ts

Expected: resolveModalRegions("openrouter/sakana/fugu-ultra", undefined) returns ["us"].

Reviewer focus

• src/sandbox/modal-regions.ts: the pin match now goes through stripRoutingPrefix. sandbox/ depends on harness/, not on benchmarks/agent-cli/.

Checklist

• Tests cover changed behavior
• Public API or configuration changes are backward compatible, or the break is documented
• Benchmark changes document dataset provenance and licensing
• No credentials, private results, or restricted dataset contents are included
• Documentation is updated where needed

Link to Devin session: https://openrouter.devinenterprise.com/sessions/4a11ad51b948470fbe1b893fd1f275f8
Open in Devin Desktop: https://openrouter.devinenterprise.com/desktop/session/4a11ad51b948470fbe1b893fd1f275f8?variant=devin
Requested by: @ayush-or

[devin-ai-integration]

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---

Original prompt from Ayush

SYSTEM:
<latest_message>
Ayush Patel (U0B8L6RNMA9) [ts=1789652370.558029]: &gt; ◦ provider region 403 from the modal sandbox, Fugu Ultra/Max terminal-bench blocked. needs sandbox region pinning or egress through OR. no PR. maybe we just support pinning sandbox region? modal accepts a param
@Devin can you make a pr to enable this and default to US in benchmark-harness / openrouter-web
read modal upstream docs if needed, see the price diff if we region pin
</latest_message>

=== BEGIN THREAD HISTORY (in #agents) ===
Ayush Patel (U0B8L6RNMA9) [ts=1789652370.558029]: &gt; ◦ provider region 403 from the modal sandbox, Fugu Ultra/Max terminal-bench blocked. needs sandbox region pinning or egress through OR. no PR. maybe we just support pinning sandbox region? modal accepts a param
@Devin can you make a pr to enable this and default to US in benchmark-harness / openrouter-web
read modal upstream docs if needed, see the price diff if we region pin
=== END THREAD HISTORY ===
Channel ID: C07UF9XLTFF
Thread URL: https://openrouter.slack.com/archives/C07UF9XLTFF/p1789652370558029?thread_ts=1789652370.558029&amp;cid=C07UF9XLTFF

The <latest_message> is the message that you should use to guide your goals + task for this session, and you should use the rest of the slack thread as context.
A [ts=...] marker on a Slack message is that message's timestamp. To act on a specific message with the slack tool (e.g. adding an emoji reaction via the reaction command), pass that value as timestamp along with the Channel ID — no extra lookup call is needed.