chore: add Dependabot configuration

[marandaneto]

💡 Motivation and Context

Add root-level Dependabot coverage for the dependency managers used by this repository: Composer for SDK dependencies, npm for the release-metadata package.json and its pnpm package-manager pin, and GitHub Actions.

All three ecosystems run weekly with a seven-day default cooldown. The configuration does not set explicit reviewers; the repository-wide CODEOWNERS rule assigns PostHog/team-client-libraries to dependency update changes.

💚 How did you test it?

• Parsed .github/dependabot.yml with Ruby's YAML parser and asserted the exact ecosystem order, complete key set, root directories, weekly intervals, seven-day cooldowns, and absence of reviewers.
• Ran pnpm install --frozen-lockfile successfully.
• Ran composer validate --no-check-publish successfully (with the repository's existing warning about the version field).
• Ran git diff --check successfully.
• Ran branch autoreview against origin/main; it reported no actionable findings.

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran pnpm change to generate a change intent file

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Implemented with Pi's implementation agent and the autoreview skill. The configuration is intentionally limited to the three package ecosystems used at the repository root, with duplicated scheduling and cooldown settings and reviewer assignment left to CODEOWNERS.

[greptile-apps]

_{Reviews (1): Last reviewed commit: "chore: add Dependabot configuration" | Re-trigger Greptile}

[github-actions]

posthog-php Compliance Report

Date: 2026-08-07 10:13:01 UTC
Duration: 95315ms

✅ All Tests Passed!

46/46 tests passed

---

Capture Tests

✅ 29/29 tests passed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	12ms
Format Validation.Event Has Uuid	✅	5ms
Format Validation.Event Has Lib Properties	✅	6ms
Format Validation.Distinct Id Is String	✅	5ms
Format Validation.Token Is Present	✅	6ms
Format Validation.Custom Properties Preserved	✅	6ms
Format Validation.Event Has Timestamp	✅	5ms
Retry Behavior.Retries On 503	✅	5311ms
Retry Behavior.Does Not Retry On 400	✅	2009ms
Retry Behavior.Does Not Retry On 401	✅	2009ms
Retry Behavior.Respects Retry After Header	✅	8015ms
Retry Behavior.Implements Backoff	✅	15729ms
Retry Behavior.Retries On 500	✅	5114ms
Retry Behavior.Retries On 502	✅	5115ms
Retry Behavior.Retries On 504	✅	5114ms
Retry Behavior.Max Retries Respected	✅	16529ms
Deduplication.Generates Unique Uuids	✅	12ms
Deduplication.Preserves Uuid On Retry	✅	5112ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	10323ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	5117ms
Deduplication.No Duplicate Events In Batch	✅	11ms
Deduplication.Different Events Have Different Uuids	✅	8ms
Compression.Sends Gzip When Enabled	✅	5ms
Batch Format.Uses Proper Batch Structure	✅	6ms
Batch Format.Flush With No Events Sends Nothing	✅	3ms
Batch Format.Multiple Events Batched Together	✅	10ms
Error Handling.Does Not Retry On 403	✅	2008ms
Error Handling.Does Not Retry On 413	✅	2009ms
Error Handling.Retries On 408	✅	5114ms

Feature_Flags Tests

✅ 17/17 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	7ms
Request Payload.Flags Request Uses V2 Query Param	✅	4ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	5ms
Request Payload.Flags Request Omits Authorization Header	✅	4ms
Request Payload.Token In Flags Body Matches Init	✅	5ms
Request Payload.Groups Round Trip	✅	4ms
Request Payload.Groups Default To Empty Object	✅	5ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	4ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	5ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	5ms
Request Lifecycle.No Flags Request On Init Alone	✅	2ms
Request Lifecycle.No Flags Request On Normal Capture	✅	6ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	7ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	4ms
Retry Behavior.Retries Flags On 502	✅	107ms
Retry Behavior.Retries Flags On 504	✅	107ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	7ms