[Oztechan/AdTrack#33] Rename AdTrace to AdTrack everywhere

[mustafaozhan]

"AdTrace" is taken on the App Store — rename the whole project to AdTrack. GitHub repos already renamed (Oztechan/AdTrack, Oztechan/adtrack-ios-credentials); local remote updated.

What changed (98 files, mechanical)

• Packages: git mv all 5 com/oztechan/adtrace/ dirs → adtrack (androidMain, commonMain, commonTest, iosMain, androidApp). Renamed AdTraceApplication.kt → AdTrackApplication.kt, AdTraceColors.kt → AdTrackColors.kt.
• Identifiers: com.oztechan.adtrace → com.oztechan.adtrack (applicationId, namespace, bundle id, OAuth redirect scheme, all package decls/imports).
• App name: AdTrace → AdTrack (APP_NAME, PRODUCT_NAME, AdTrack.ipa, gym output_name, strings.xml, rootProject.name).
• CI/infra: Slack adtrace-github → adtrack-github; Matchfile git_url → adtrack-ios-credentials; Fastfile/Appfile ids.
• 0 occurrences of adtrace/AdTrace remain in tracked files.

Verified

Forced clean recompile of :common Android + iOS targets + unit tests (--rerun-tasks, 22 tasks) → BUILD SUCCESSFUL.

Follow-ups (not in this PR)

• Rebase the 3 open PRs ([Oztechan/AdTrack#26] Make Android CI variant-aware (Debug on push, Release on schedule) #27, [Oztechan/AdTrack#28] Add release deployment workflow (Google Play internal + TestFlight) #29, [Oztechan/AdTrack#31] Port CCC version scheme + iOS build-number sync (agvtool) #32) onto this and rename their adtrace refs — they'll conflict until then.
• External (you): Firebase project/apps for com.oztechan.adtrack(.debug), Slack adtrack-github channel, Apple bundle ids + fastlane match re-seed, Play package, regenerate google-services.json + update secret values.
• Local folder: mv …/Oztechan/AdTrace …/Oztechan/AdTrack and reopen (after merge).

Resolves #33