Add unit type labels and member counts to tree nodes
epic-organizational-hierarchy-management-core-services-task-018 — Enhance each HierarchyTreeView node to display the unit type label (e.g., Region, Chapter, Local) resolved via the OrganizationLabelsProvider for per-org terminology, and the member count pulled from the hierarchy cache. Use design token typography and the unified entity color system for type badges.
Acceptance Criteria
Technical Requirements
Execution Context
Tier 7 - 84 tasks
Can start after Tier 6 completes
Implementation Notes
Extract UnitTypeBadge as a reusable widget (lib/shared/widgets/unit_type_badge.dart) because it will likely be used outside the hierarchy tree (e.g., contact cards, search results). The badge color lookup should be a pure function: Color resolveUnitTypeColor(String unitType, AppColorTokens tokens) — this makes it unit-testable without Flutter context. OrganizationLabelsProvider should expose a synchronous selector so HierarchyNodeTile does not need to handle loading states for labels (labels should be loaded once at app startup). Keep member count formatting consistent with the rest of the app — use NumberFormat.decimalPattern() from the intl package if already in the dependency tree, otherwise use a simple toString() with a suffix string from the localization layer.
Testing Requirements
Widget tests (flutter_test): override OrganizationLabelsProvider with a stub returning 'Region' for unitType 'region'; assert badge displays 'Region'. Override with null return; assert no badge is rendered. Provide a HierarchyNode with memberCount = 42; assert '42' appears in the rendered widget. Provide memberCount = null; assert no member count text is rendered.
Test that label and count update when ProviderScope is updated mid-test to simulate a cache refresh. Verify UnitTypeBadge does not overflow with a 30-character label string.
Injecting all unit assignment IDs into JWT claims for users assigned to many units (up to 5 for NHF peer mentors, many more for national coordinators) may exceed JWT size limits, causing authentication failures.
Mitigation & Contingency
Mitigation: Store unit IDs in a Supabase session variable or a dedicated Postgres function rather than embedding them directly in the JWT payload. Use set_config('app.unit_ids', ...) within RLS helper functions querying the assignments table at policy evaluation time.
Contingency: Fall back to querying the unit_assignments table directly within RLS policies using the authenticated user ID, accepting a small per-query overhead in exchange for removing the JWT size constraint.
Rendering 1,400+ nodes in a recursive Flutter tree widget may cause jank or memory pressure on lower-end devices used by field peer mentors, degrading the admin experience.
Mitigation & Contingency
Mitigation: Implement lazy tree expansion — only the root level is rendered on initial load. Child nodes are rendered on demand when the parent is expanded. Use const constructors and ListView.builder for all node lists to minimize rebuild scope.
Contingency: Add a search/filter bar that scopes the visible tree to matching nodes, reducing the visible node count. Provide a 'flat list' fallback view for administrators who prefer searching over browsing the tree.
Requirements for what constitutes a valid hierarchy structure may expand during NHF sign-off (e.g., mandatory coordinator assignments per chapter, minimum member counts per region), requiring repeated validator redesign.
Mitigation & Contingency
Mitigation: Design the validator as a pluggable rule engine where each check is a discrete, independently testable function. New rules can be added without changing the core validation orchestration. Surface all rules in a configuration table per organization.
Contingency: Defer non-blocking validation rules to warning-level feedback rather than hard blocks, allowing structural changes to proceed while flagging potential issues for admin review.
Deploying RLS policy migrations to a shared Supabase project used by multiple organizations simultaneously could lock tables or interrupt active sessions, causing downtime during production migration.
Mitigation & Contingency
Mitigation: Write all RLS policies as CREATE POLICY IF NOT EXISTS statements. Schedule migrations during off-peak hours. Use Supabase's migration preview environment to validate policies against production data shapes before applying.
Contingency: Prepare rollback migration scripts for every RLS policy. If a migration causes issues, execute the rollback immediately and re-test the policy logic in staging before reattempting.