fix(surveys): prevent color hex overflow

[dustinbyrne]

💡 Motivation and Context

Fixes #794.

Survey appearance colors come from remote config and are passed to UIColor(hex:). Seven-digit values were expanded beyond 32 bits, while values longer than eight digits remained too wide, causing Swift to trap when narrowing the parsed value to UInt32.

This change right-pads seven-digit values with one zero, preserves exactly eight digits, and truncates longer values to their first eight digits before parsing. Existing shorter color formats keep their current behavior.

💚 How did you test it?

• make test — 765 tests passed
• make testOniOSSimulator — 875 tests passed, including the new regression test
• make lint — passed with pre-existing warnings
• pnpm changeset status — recognized the patch changeset
• make buildSdk — iOS, macOS, Mac Catalyst, and Swift Package builds passed; the remaining platform builds could not run because the local Xcode installation does not include the tvOS 26.5 runtime

📝 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

• Added and validated a patch changeset.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Implemented with the Pi coding agent after the human directed the normalization behavior and discussed the backend reachability. A fresh read-only reviewer found no blockers. The agent session is not linked because it contains a test-project credential.

[github-actions]

posthog-ios Compliance Report

Date: 2026-09-02 04:37:38 UTC
Duration: 224566ms

✅ All Tests Passed!

45/45 tests passed

---

Capture Tests

✅ 29/29 tests passed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	2917ms
Format Validation.Event Has Uuid	✅	2767ms
Format Validation.Event Has Lib Properties	✅	2817ms
Format Validation.Distinct Id Is String	✅	2789ms
Format Validation.Token Is Present	✅	2725ms
Format Validation.Custom Properties Preserved	✅	310ms
Format Validation.Event Has Timestamp	✅	2802ms
Retry Behavior.Retries On 503	✅	11668ms
Retry Behavior.Does Not Retry On 400	✅	4793ms
Retry Behavior.Does Not Retry On 401	✅	4723ms
Retry Behavior.Respects Retry After Header	✅	7822ms
Retry Behavior.Implements Backoff	✅	19209ms
Retry Behavior.Retries On 500	✅	5410ms
Retry Behavior.Retries On 502	✅	9255ms
Retry Behavior.Retries On 504	✅	9248ms
Retry Behavior.Max Retries Respected	✅	21655ms
Deduplication.Generates Unique Uuids	✅	2936ms
Deduplication.Preserves Uuid On Retry	✅	8786ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	16337ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	7911ms
Deduplication.No Duplicate Events In Batch	✅	2939ms
Deduplication.Different Events Have Different Uuids	✅	2717ms
Compression.Sends Gzip When Enabled	✅	2769ms
Batch Format.Uses Proper Batch Structure	✅	2640ms
Batch Format.Flush With No Events Sends Nothing	✅	212ms
Batch Format.Multiple Events Batched Together	✅	2860ms
Error Handling.Does Not Retry On 403	✅	4754ms
Error Handling.Does Not Retry On 413	✅	4787ms
Error Handling.Retries On 408	✅	8865ms

Feature_Flags Tests

✅ 16/16 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	2789ms
Request Payload.Flags Request Uses V2 Query Param	✅	2785ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	2713ms
Request Payload.Flags Request Omits Authorization Header	✅	2781ms
Request Payload.Token In Flags Body Matches Init	✅	2839ms
Request Payload.Groups Round Trip	✅	2665ms
Request Payload.Groups Default To Empty Object	✅	2737ms
Request Payload.Person Properties Distinct Id Auto Populated When Caller Omits It	✅	2700ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	2720ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	2800ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	2720ms
Request Lifecycle.No Flags Request On Init Alone	✅	61ms
Request Lifecycle.No Flags Request On Normal Capture	✅	2760ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	5391ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	2811ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	2973ms

[greptile-apps]

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