[onamfc]

What changed

• DeepLinkData gains nullable confidenceScore (double?), matchedFactors (List<String>?), attributionMethod (String?) and competingLinks (int?). The install endpoint sends them inside deepLinkData on a match, so they reach the app through onDeferredDeepLink. The resolve endpoint never sends them, so they are null on a direct open. fromJson/toJson, ==, hashCode, toString and mergingUrlParameters include them.
• InstallResponse gains nullable attributionMethod ("fingerprint" or "none") and competingLinks, as optional named constructor parameters. The response the SDK builds on later launches (from the stored install data) leaves both null rather than inventing values.
• The new fields are read by small lenient readers (lib/models/match_certainty_json.dart): a missing or wrongly typed value becomes null, and a whole-number double (2.0) becomes an int. A bad value in one of these informational fields never drops the deep link or fails the install response.
• The install's deep link is stored as DeepLinkData JSON, so the fields round-trip through getInstallData(); data stored by earlier versions decodes with them null.
• Dartdoc on competingLinks explains what it means; README has a "How certain is the match?" section with an example; CHANGELOG entry; version 0.5.0 in pubspec.yaml, SdkInfo.version and example/pubspec.lock. Generated *.g.dart files rebuilt with build_runner.

Why

competingLinks tells an app whether other links on the same network were also in contention for the install. 0 means no other link was; above 0, another device's tap may be what led to this install, so an app acting on a sensitive link (a sign-in, a gift) can treat the match as unverified, for example by asking the user to confirm. The match score and factors were already sent on the deferred deep link but not exposed by the SDK.

Tests

• New model tests: parsing with and without the new fields, "none" for organic, a double competingLinks, wrongly typed values read as null, JSON round-trip, equality/hashCode, mergingUrlParameters keeping the fields.
• Storage tests: save then load round-trip of the new fields, and decoding install data in the shape earlier versions stored.
• Attribution manager: later launches return null for both new InstallResponse fields.
• flutter test (164 passed), flutter analyze (no issues), dart format --output=none --set-exit-if-changed . (clean), dart run build_runner build --delete-conflicting-outputs (no diff in lib), flutter pub publish --dry-run (0 warnings).