feat(tasks): rebind sandbox GitHub identity and git author to the actor

[VojtechBartos]

Problem

Stacked on #69618 (which rebinds the PostHog MCP identity per message). Commits and PRs from the agent sandbox are still authored by whoever created the task, even when a teammate is the one driving the turn — their work lands under someone else's name.

Changes

Extends the per-message rebind to GitHub: when the acting user has a personal GitHub install covering the task's repository, the live sandbox's git remote token, GITHUB_TOKEN/GH_TOKEN, and GIT_AUTHOR_*/GIT_COMMITTER_* are swapped via the agentsh env file — which the exec wrapper re-sources per command, so the change reaches the agent's later git/gh calls (including gh pr create) with no sandbox restart. The facade's rebind_sandbox_identity_for_user gains the GitHub half; the Slack layer is untouched.

Guardrails, since two background systems re-apply GitHub credentials and would otherwise fight a swap:

• The credential refresh loop resolves the swapped integration instead of the task creator's, and token-rotation propagation skips sandboxes whose identity was swapped away — neither silently reverts a swap.
• A github_user identity mark lets same-actor messages skip integration resolution entirely (a DB query and, on a stale repo cache, a paginated GitHub API sync per message otherwise), and it survives swaps — including switching back to the creator.
• Sandbox liveness is checked before the token-rotation lock, so a dead sandbox never triggers a mint-and-revoke.
• Only user-authored, non-caller-token runs are ever swapped; actors without a covering install keep the previous identity (their message still goes through — they simply keep authoring as before).

How did you test this code?

Automated only; manual multiplayer verification planned with the queue-workflow dev rollout.

• Six tests in test_sandbox_credentials.py, each pinning a distinct regression: the swap applies token + git author through the shared apply helper in one env write and records both identity marks; actors without a covering install, bot-authored runs, and same-identity messages are skipped; switching back to the creator re-applies their identity; and the creator fast path skips integration resolution on never-swapped runs.
• Full tasks process_task + slack_app forwarding suites green on this branch and on the base branch independently.

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

Docs update

N/A, internal credential mechanics behind the queue-workflow flag.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Authored with Claude Code; split out of a combined MCP+GitHub identity PR so this tasks-owned half reviews independently. Decisions: identity marks live in the tasks cache alongside the MCP one (durable TaskRun.state storage is a named follow-up, as is including swapped-to sandboxes in rotation propagation); the swap reuses apply_github_credentials_to_sandbox via a new extra_env parameter so there is one definition of where a sandbox reads GitHub tokens from; the agentsh env-file mechanism was verified to re-source per command, so no sandbox-side changes were needed.

[trunk-io]

     

View Full Report ↗︎ ⋅ Docs

[github-actions]

🤖 CI report

ℹ️ ClickHouse migration SQL — 1 migration(s)

ClickHouse migration SQL per cloud environment

• unset
  • all

    DROP TABLE IF EXISTS property_values_mv

    CREATE MATERIALIZED VIEW IF NOT EXISTS property_values_mv
    TO property_values
    AS SELECT
        team_id,
        property_type,
        property_key,
        property_value,
        property_count,
        coalesce(_timestamp, now()) as last_seen
    FROM posthog_test.kafka_property_values

• US, EU
  • aux

    DROP TABLE IF EXISTS property_values_mv

    CREATE MATERIALIZED VIEW IF NOT EXISTS property_values_mv
    TO property_values
    AS SELECT
        team_id,
        property_type,
        property_key,
        property_value,
        property_count,
        coalesce(_timestamp, now()) as last_seen
    FROM posthog_test.kafka_property_values

• DEV
  • data

    DROP TABLE IF EXISTS property_values_mv

    CREATE MATERIALIZED VIEW IF NOT EXISTS property_values_mv
    TO property_values
    AS SELECT
        team_id,
        property_type,
        property_key,
        property_value,
        property_count,
        coalesce(_timestamp, now()) as last_seen
    FROM posthog_test.kafka_property_values

[VojtechBartos]

Closing to rebuild on master's run-state actor design (#66212). The replacement follows #70454's transition-gate pattern so MCP and GitHub identity switch in the same place.