feat(task-engine): add semantic task frontend

[skywhite1024]

Stack

• Layer: 2/6
• Base: ljd/gen-sim-refactor-02-seedgraph-contracts
• Depends on: feat(gen-sim): add task contracts and scene authoring boundary #533
• Followed by: feat(action-engine): add planning and bundle generation #535

Description

This PR adds the scene-independent semantic TaskAgent frontend. It generates and validates multiple structured task candidates, deterministically derives SceneRequest and SuccessSpec contracts, deduplicates candidates, and fails closed on invalid model output.

Grounding, planning, and simulator execution remain in later layers.

Type of change

• Bug fix
• Enhancement
• New feature
• Breaking change
• Documentation update

Validation

• black --check --diff --color ./
• python docs/scripts/check_api_docs.py
• pytest tests/gen_sim/task_engine/test_agent.py tests/gen_sim/task_engine/test_interpretation.py -q (14 passed)

Checklist

• Code is formatted with Black 26.3.1
• Public API documentation is aligned
• Focused tests cover the semantic frontend
• This layer is independently importable and testable

[greptile-apps]

Greptile Summary

The PR adds scene-independent semantic task interpretation, candidate generation, scene grounding, TaskSpec assembly, scene handoff validation, and simulator configuration generation.

• Introduces strict Task Engine drafts, scene requests, success specifications, and candidate-set contracts.
• Adds LLM-backed instruction interpretation and scene-reference grounding for E1–E9 tasks.
• Adds Action Engine TaskSpec lowering and scene handoff validation.
• Adds robot-profile-driven simulator and agent configuration builders.

Confidence Score: 4/5

The PR is not safe to merge until the simulator templates required by build_fast_gym_config are added or its template references are corrected.

The semantic interpretation and grounding contracts appear internally consistent, but every invocation of the new gym-config builder reaches missing packaged templates and raises FileNotFoundError before producing a configuration.

Files Needing Attention: embodichain/gen_sim/action_engine/generation/config_builder.py and embodichain/gen_sim/action_engine/generation/templates/

Important Files Changed

Filename	Overview
embodichain/gen_sim/task_engine/interpretation.py	Adds strict LLM instruction interpretation, normalization, transport configuration, and intent validation.
embodichain/gen_sim/task_engine/agent.py	Adds concurrent candidate generation, canonicalization, deduplication, and vote aggregation.
embodichain/gen_sim/task_engine/contracts.py	Defines and validates JSON-safe task drafts, scene requests, success specifications, and candidate sets.
embodichain/gen_sim/action_engine/tasks/grounding.py	Adds fail-closed semantic scene-reference grounding with cardinality and eligibility checks.
embodichain/gen_sim/action_engine/tasks/interpretation.py	Bridges validated Task Engine intents into grounded Action Engine TaskSpecs.
embodichain/gen_sim/action_engine/tasks/assembly.py	Adds scene inventory modeling and E1–E9 TaskSpec and requirement assembly.
embodichain/gen_sim/action_engine/generation/config_builder.py	Adds simulator and agent manifest generation, but its required robot, sensor, and light templates are absent, making the new gym-config API fail immediately.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart LR
    I[Task instruction] --> TI[Task Engine interpretation]
    TI --> D[Validated semantic draft]
    D --> G[Scene-reference grounding]
    S[Scene inventory] --> G
    G --> TS[Grounded TaskSpec and scene requirements]
    TS --> H[Scene handoff validation]
    H --> C[Simulator and agent config generation]
    C --> R[Action Engine runtime]

Loading

Prompt To Fix All With AI

### Issue 1
embodichain/gen_sim/action_engine/generation/config_builder.py:225
**Required configuration templates are missing**

When `build_fast_gym_config()` runs, `_make_robot()` and the subsequent sensor and light loaders reference template files that are absent from this directory, causing generation to raise `FileNotFoundError` before returning a gym configuration. A/B mode also requires the absent `vlm_sensors.json`; please include the referenced templates or correct these references.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: "feat(task-engine): add semantic task int..." | Re-trigger Greptile}

[greptile-apps]

Required configuration templates are missing

When build_fast_gym_config() runs, _make_robot() and the subsequent sensor and light loaders reference template files that are absent from this directory, causing generation to raise FileNotFoundError before returning a gym configuration. A/B mode also requires the absent vlm_sensors.json; please include the referenced templates or correct these references.

Prompt To Fix With AI

This is a comment left during a code review.
Path: embodichain/gen_sim/action_engine/generation/config_builder.py
Line: 225

Comment:
**Required configuration templates are missing**

When `build_fast_gym_config()` runs, `_make_robot()` and the subsequent sensor and light loaders reference template files that are absent from this directory, causing generation to raise `FileNotFoundError` before returning a gym configuration. A/B mode also requires the absent `vlm_sensors.json`; please include the referenced templates or correct these references.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.