RulesEngine: Maven Central publishing wiring

[ajpallares]

Resolves SDK-4338

Stacked on top of: #3478 — :rules-engine: internal skeleton module.

Description

This PR flips on every Maven Central publishing piece for the :rules-engine module:

• Drops the :rules-engine short-circuit in ConfigureConditionalPublishing so com.vanniktech.maven.publish gets applied again.
• Adds the mavenPublishing { … } block (AndroidSingleVariantLibrary("defaultsRelease", …)), gated by plugins.withId("com.vanniktech.maven.publish") { … } so the custom-entitlement-computation deploy lane keeps working.
• Adds :rules-engine:metalavaGenerateSignatureDefaultsRelease to scripts/api-dump.sh so CI catches API drift in rules-engine/api.txt.
• Adds the dokkaHtmlPartial suppression so the published multi-module dokka site doesn't include an empty rules-engine page.
• Re-adds the api(project(":rules-engine")) constraint in :bom.

The metalava { … } config + the committed rules-engine/api.txt baseline already live in the skeleton PR (#3478) — they're standard hygiene for every revenuecat.public.library module — so this PR just wires them into CI enforcement.

Why a separate PR?

The skeleton itself (#3478) ships a kotlin android library gated by @InternalRulesEngineAPI with no functionality and no consumer. We deliberately split publishing wiring out so the skeleton can land independently and we don't start publishing empty purchases-rules-engine versions to Maven Central on every SDK release (Maven Central versions are immutable, so once 10.7.0 exists we're committed to keeping it published forever).

This PR is kept open as a draft and will be merged alongside (or just before) the first PR that introduces a real consumer of :rules-engine. Until then, the skeleton compiles, runs tests, and gets detekt'd on every PR without producing any external artifact.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.89%. Comparing base (aed6e2f) to head (19bdc99).

Additional details and impacted files

@@                       Coverage Diff                       @@
##           pallares/rules-engine-skeleton    #3488   +/-   ##
===============================================================
  Coverage                           79.89%   79.89%           
===============================================================
  Files                                 369      369           
  Lines                               14871    14871           
  Branches                             2048     2048           
===============================================================
  Hits                                11881    11881           
  Misses                               2157     2157           
  Partials                              833      833           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.