fix(android): show interrupt reason instead of bare Response/Run interrupted

[ophirhan]

Summary

When a Gateway/API turn is cancelled, Android Chat often showed a bare Response interrupted or Run interrupted label even if the host already sent a reason (content, error, interrupt_reason, or turn_exit_reason). This PR prefers any non-placeholder server text for the user-visible error path.

Related (hermes-agent — server delivery of interrupt reasons):

• [Bug]: Interrupted turn (exit 130) delivers zero user feedback — silent death until user re-pings; no distinction between deliberate stop and client disconnect NousResearch/hermes-agent#84207
• fix(agent): visible closing message and structured stop_kind for interrupted turns NousResearch/hermes-agent#84236

Full end-to-end “always an explanation” still depends on the host emitting a reason (agent fix above or equivalent). This client change is defensive: when a reason is present it is shown; when absent, existing bare fallbacks remain.

Changes

• Add SessionEventPayload.resolveInterruptMessage() (and bare-placeholder detection) prioritizing interrupt_reason / error / content fields, then a humanized turn_exit_reason.
• Wire resolve helpers through Gateway SSE (GatewayEventMapper, ChatHandler) and API run streams (HermesApiClient).
• Unit coverage in InterruptReasonResolveTest.
• CHANGELOG Unreleased note for the user-visible Android behavior.

Verification

• ./gradlew :app:testSideloadDebugUnitTest --tests com.hermesandroid.relay.network.upstream.models.InterruptReasonResolveTest — BUILD SUCCESSFUL (focused class green; full sideload unit test task also completed successfully on this branch).
• Android lint: not re-run for this PR cut (rationale: small mapping-only change + focused unit tests).
• On-device UI dogfood: pass (OnePlus CPH2653, sideload Hermes Relay, 2026-09-27 ~07:12 IDT). Forced Stop mid-turn; chat showed reasoned interrupt text (not bare Response/Run interrupted).

Screenshots

Device proof (OnePlus CPH2653 / Hermes Relay sideload). Cancelled turn shows:

Operation interrupted: explicit stop requested.

Plus the standard recovery banner (“Hermes couldn’t complete this response” with Details / Retry / Dismiss). No layout redesign — copy only.

(Image attached in the following PR comment.)

Compatibility / risk

• Standard Hermes / unmodified upstream hosts: safe. Missing reason fields keep prior “Response interrupted” / “Run interrupted” fallbacks.
• No migrations, no plugin/server changes in this PR.
• Rollout/rollback: client-only; revert commit restores previous labels.
• Does not claim CLI/gateway interrupt delivery is fixed; that remains on hermes-agent (#84207 / #84236).

Lineage / contributor credit

• Source PR(s): N/A
• Attribution preserved by: N/A

Checklist

• Target branch is dev, unless this is a dev → main release PR or a focused production-tag hotfix PR to main
• Scope is focused and related issues/PRs are linked
• Android changes: lint and focused tests ran, or rationale is listed above
• Translation changes: locale validation/review ran, or N/A is listed above
• Server/plugin changes: focused tests ran, or N/A/rationale is listed above
• Desktop changes: build/tests ran, or N/A/rationale is listed above
• Docs/site changes: build or link/route checks ran, or N/A/rationale is listed above
• UI changes were tested on a relevant device/emulator/desktop surface, or the missing proof is stated above
• Commit messages follow Conventional Commits
• CHANGELOG.md is updated for user-visible changes, or N/A is listed above
• Public writing hygiene checked: no secrets, private infrastructure, personal names, or AI/process narration
• Salvaged/replacement work links source PRs and preserves contributor authorship, or N/A is listed above

[hermes-relay-triage]

🤖 Hermes-Relay automated PR intake

Thanks for opening this focused Android interrupt-reason display fix!

Intake evidence looks solid: the PR targets dev, all template sections are filled, related hermes-agent issue/PR links are present, lineage is marked N/A, and the checklist is checked. Verification lists an exact focused unit-test command with BUILD SUCCESSFUL, and it explicitly notes Android lint was not re-run plus on-device UI proof of a cancelled turn is still outstanding. Screenshots correctly say this is copy-only, with device proof outstanding. Compatibility notes the client-only fallback and that host interrupt delivery is out of scope. CI is still in progress on Android lint, build, test, and the vanilla-upstream route contract; that state is informational only and not a review of correctness.

Nothing else is missing for intake. The outstanding device proof is already stated, so no extra checklist item is needed before review.

A maintainer will review the mapping change and decide whether the stated missing on-device proof should be collected before merge.

[ophirhan]

Device proof (on-device)

• Device: OnePlus CPH2653 (sideload Hermes Relay)
• Time: 2026-09-27 ~07:12 IDT
• Method: forced Stop mid-turn (not a spontaneous ops failure)
• Exact interrupt line shown in chat:

Operation interrupted: explicit stop requested.

This is not a bare Response interrupted / Run interrupted / Operation interrupted. placeholder.

[ophirhan]

Rebased onto current dev (force-with-lease). Hygiene-scan clean.

Interrupt-reason display (no bare Response/Run interrupted) is still independent of the quiet-turn ownership work. Android + contract checks re-running.

Ready for review when CI is green.