feat(env): add Go2 Manager-Based reward parity terms

[TATP-233]

Summary

• add six task-owned NumPy reward terms for independent planar/yaw tracking, vertical/roll-pitch penalties, flat root height, and L1 default-pose deviation
• preserve current Go2 flat equations while using community func + params, std, command-manager, and SceneEntityCfg structure
• validate command/state shape and finite values at the nearest term boundary
• leave pinned generic MDP terms, production Go2 registration/config, backend, DR, runner, and IPC unchanged

Scope accounting

• files: 2 modified
• additions: 270
• deletions: 2
• source-derived: 0
• mechanical: 0
• task-owned code: 147 additions / 2 replaced lines
• tests: 123 additions

Local validation

• focused: 10 passed
• adjacent entity/manager/reward regression: 53 passed
• ruff: passed
• mypy: passed
• pyright: passed
• make test-all: passed (1991 passed, 27 skipped, 276 deselected, 1 xfailed; benchmark module mode 32/33 and script mode 33/34, with one platform-optional MLX skip in each mode)

Per the #1042 child workflow, these gates ran locally on final head a0d7c2ec; remote CI/Docs are intentionally not triggered.

Refs #1042
Closes #1084