Add source-scoped manga recommendations

[Kom1ch1]

Summary

• Adds More by the same creators and Similar manga rows to manga details.
• Keeps every recommendation scoped to the manga's current source.
• Uses conservative creator/tag metadata, source-scoped identity checks, de-duplication, ranking, diversity re-ranking, and quality-weighted sampling.
• Uses local initialized manga by default; optional source network recommendations are disabled until explicitly enabled per source.

Privacy and source load

• No AI and no reading-history upload.
• No site-specific providers or domain checks.
• No popular/latest fallback.
• Network mode is serialized with a minimum one-second interval, a four-request page budget, at most two detail checks, and stops the page on HTTP 429 while preserving existing cards.
• AniList is queried only when an existing track ID is available, and results must map exactly back to the current source.

Validation

• :app:testStandardDebugUnitTest (including 31 recommendation tests)
• :app:lintStandardDebug
• :app:assembleStandardDebug
• git diff --check

Screenshots

More by the same creators	Similar manga

Both screenshots use non-sensitive English manga and demonstrate the two independent recommendation rows on a phone layout.

This remains a draft for initial maintainer feedback.