Checkpoint config-driven env GRPO eval work

[ProfSynapse]

Summary:

• Adds the current workspace multistep GRPO projection and refreshed lean SFT datasets/config.
• Adds workspace multi-turn eval scenario coverage plus focused tests for agentic loops, environment search, response scoping, and stage gates.
• Adds generic environment execution/scoring support for configured tool aliases so path scoring can match schema-facing commands without hardcoding a toolset.
• Adds env generation diagnostics, SFT prompt alignment migration, local GRPO image, and PEFT merge helper.

Validation:

• python -m pytest tests/shared/test_agentic_loop.py tests/shared/test_local_environment_search.py tests/shared/test_workspace_multiturn_scenarios.py tests/synthchat/test_agentic_episode_messages.py tests/synthchat/test_response_scope_message_selection.py tests/synthchat/test_stage_gates.py
• python .skills/scripts/sync_skill_trees.py --check
• git diff --check