Feat: Replace pagination bar with numbered page buttons and chevron controls

Adds « ‹ [1][2][3][4] › » navigation to the library. Page window
slides to keep the current page in view. Prev/next/first/last controls
are always rendered but disabled at their respective bounds. Also wires
up karmaConfig in angular.json so FirefoxHeadless is used for tests.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

specs/018-pagination-controls/checklists/requirements.md

@@ -0,0 +1,30 @@
+# Specification Quality Checklist: Pagination Controls Redesign
+
+**Purpose**: Validate specification completeness and quality before proceeding to planning
+**Created**: 2026-05-10
+**Feature**: [spec.md](../spec.md)
+
+## Content Quality
+
+- [X] No implementation details (languages, frameworks, APIs)
+- [X] Focused on user value and business needs
+- [X] Written for non-technical stakeholders
+- [X] All mandatory sections completed
+
+## Requirement Completeness
+
+- [X] No [NEEDS CLARIFICATION] markers remain
+- [X] Requirements are testable and unambiguous
+- [X] Success criteria are measurable
+- [X] Success criteria are technology-agnostic (no implementation details)
+- [X] All acceptance scenarios are defined
+- [X] Edge cases are identified
+- [X] Scope is clearly bounded
+- [X] Dependencies and assumptions identified
+
+## Feature Readiness
+
+- [X] All functional requirements have clear acceptance criteria
+- [X] User scenarios cover primary flows
+- [X] Feature meets measurable outcomes defined in Success Criteria
+- [X] No implementation details leak into specification