[DYN-021] Adaptive collection navigation and filtering

[veryCrunchy]

Roadmap

• Task ID: DYN-021
• Priority: P0
• Parent epic: [EPIC] Adaptive Nextcloud apps #15
• Related foundation: [DYN-004] Semantic entity recognition #44, [DYN-006] Relationship and nested-resource planner #46, [DYN-007] Native list/detail/table/board/dashboard selection #47, [DYN-011] Tables presentation #51

Acceptance criteria

• Select among multiple discovered collections with an adaptive compact selector on phones and persistent navigation on larger windows.
• Search loaded records without leaking queries across unrelated resource or scope identities.
• Infer bounded low-cardinality filters from verified field semantics and avoid turning unique values into facets.
• Support deterministic server order, ascending, and descending sorting.
• Preserve parent scope and selected collection while navigating, filtering, and recovering from empty results.
• Keep the implementation schema-driven with no app-ID branches.
• Cover touch, keyboard, narrow phone, large phone, and desktop behavior with synthetic fixtures and visual QA.
• Show loading, empty, no-results, cached-error, and retry states without raw IDs or contract labels.