feat(ci): mship companion pr check

[Sg312]

Summary

Adds companion ci check to check for drift with mothership service
Companion: https://github.com/simstudioai/copilot/pull/309

Type of Change

• New feature

Testing

Manual

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

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Project	Deployment	Actions	Updated (UTC)
docs	Ready	Preview, Comment	Jun 16, 2026 12:44am

[greptile-apps]

Greptile Summary

This PR introduces a new GitHub Actions workflow that detects cross-repo "Companion:" PR declarations in PR descriptions and posts a sticky comment indicating whether those companion PRs have been merged, keeping the simstudioai/sim and a paired repo in lockstep.

• New workflow (companion-pr-check.yml): triggers on pull_request events for staging/main and on a */30 * * * * schedule; parses "Companion:" trailers and task-list refs from PR bodies, fetches companion PR state via a CROSS_REPO_TOKEN secret, and upserts a sticky comment with ✅/⚠️/❌ status per companion.
• Release-PR aggregation: for PRs targeting main, it also walks squash-merge commit messages to collect companion declarations from the feature PRs bundled into the release.
• Label management: applies a has-companion label when companions are found, but never removes it — leaving a stale label when companions are later deleted from the description or when the scheduled run re-evaluates a PR that no longer has companions.

Confidence Score: 3/5

The workflow is safe to merge as a non-blocking informational check, but two logic gaps mean it will not behave as documented in common situations.

The has-companion label is applied but never removed, so PRs whose descriptions are later edited to drop companion declarations will carry a stale label forever. Separately, the scheduled refresh cron will silently do nothing until this workflow file also exists on the default branch — meaning the primary motivation for the schedule (catching companions that merge after this PR opens) won't work in the interim period.

companion-pr-check.yml — the label-removal path and the scheduled-run default-branch dependency both need attention before the workflow behaves as its comments describe.

Important Files Changed

Filename	Overview
.github/workflows/companion-pr-check.yml	New CI workflow that posts a sticky comment and applies a has-companion label when a PR declares cross-repo companion PRs. Label is never removed when companions are cleared from the description, and the scheduled refresh is a no-op until the file lands on the default branch.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A([Trigger]) --> B{Event type?}
    B -->|pull_request| C[checkPR: context.payload.pull_request]
    B -->|schedule / workflow_dispatch| D[List open PRs on staging + main]
    D --> E[checkPR: each PR]
    C --> F[collectCompanions]
    E --> F
    F --> G{PR targets main?}
    G -->|yes| H[Fetch commits → extract squash-merge PR numbers → parse each feature PR body]
    G -->|no| I[Parse PR body only]
    H --> J[Deduplicated companion list]
    I --> J
    J --> K{Any companions?}
    K -->|no| L[Delete sticky comment — label NOT removed]
    K -->|yes| M[ensureLabel + addLabels: has-companion]
    M --> N{CROSS_REPO_TOKEN set?}
    N -->|no| O[❓ could not verify]
    N -->|yes| P[cross.rest.pulls.get for each companion]
    P --> Q{cp.merged?}
    Q -->|yes + correct base| R[✅ line]
    Q -->|yes + wrong base| S[⚠️ line, warn=true]
    Q -->|no| T[❌ line, warn=true]
    P -->|error| U[❓ line, warn=true]
    R & S & T & U & O --> V[upsert sticky comment]

Loading

%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
flowchart TD
    A([Trigger]) --> B{Event type?}
    B -->|pull_request| C[checkPR: context.payload.pull_request]
    B -->|schedule / workflow_dispatch| D[List open PRs on staging + main]
    D --> E[checkPR: each PR]
    C --> F[collectCompanions]
    E --> F
    F --> G{PR targets main?}
    G -->|yes| H[Fetch commits → extract squash-merge PR numbers → parse each feature PR body]
    G -->|no| I[Parse PR body only]
    H --> J[Deduplicated companion list]
    I --> J
    J --> K{Any companions?}
    K -->|no| L[Delete sticky comment — label NOT removed]
    K -->|yes| M[ensureLabel + addLabels: has-companion]
    M --> N{CROSS_REPO_TOKEN set?}
    N -->|no| O[❓ could not verify]
    N -->|yes| P[cross.rest.pulls.get for each companion]
    P --> Q{cp.merged?}
    Q -->|yes + correct base| R[✅ line]
    Q -->|yes + wrong base| S[⚠️ line, warn=true]
    Q -->|no| T[❌ line, warn=true]
    P -->|error| U[❓ line, warn=true]
    R & S & T & U & O --> V[upsert sticky comment]

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_{Reviews (1): Last reviewed commit: "ci(companion): aggregate companions acro..." | Re-trigger Greptile}

[github-actions]

⚠️ Cross-repo companion check

One or more companion PRs aren't merged into staging yet. Merging this without them will leave copilot and sim out of sync — merge them in lockstep.

• ❌ simstudioai/copilot#309 — OPEN, not merged (targets staging) — ci(companion): cross-repo companion-PR warning + mship-release