feat(tools): add Team Workload Balancer V2 team tool

[fadesany]

Closes #710

Summary

Implements the core logic for the Team Workload Balancer tool as a self-contained, folder-local module under tools/v2/team/team-workload-balancer/.

Deliverables

• Types (types.ts): TeamMember, WorkloadItem, WorkloadMetrics, BalancerConfig, FetchState, and more
• Fixtures (fixtures/): Deterministic team members (4) and workload items (12) with varying priorities, statuses, and capacities
• Service (services/workload-service.ts): Core balancing algorithms with three strategies (least-loaded, round-robin, capacity-weighted), metrics calculation, imbalance scoring, and simulated async delay/failure
• React hook (hooks/use-workload-balancer.ts): useReducer-based state management covering loading, empty, error, and success states for all data slices
• Tests (tests/workload-balancer.test.mjs): 19 tests covering fixtures, metrics, balancing, and edge cases — all passing
• Docs (docs/): Review notes and test plan

Acceptance criteria

• Core logic is implemented without linking into the main app
• Inputs, outputs, loading states, and error states are documented
• No live network calls, secrets, or production data are introduced
• Files changed by this issue are limited to tools/v2/team/team-workload-balancer/
• The contribution is reviewable as a self-contained mini-product change

[kryputh]

@fadesany fix conflict

[kryputh]

@fadesany fix conflict

[kryputh]

@fadesany fix conflict

[fadesany]

fixed please merge