Add canonical streaming adapter layer for OpenAI

[tanaysd]

Summary

• add the canonical adapter protocol and event dataclasses under foundry.adapters
• implement an OpenAI streaming adapter that normalizes provider chunks into deterministic events
• document the adapter contract and add contract/parity/edge tests backed by the offline fake client

Testing

• pytest tests/test_openai_adapter_contract.py tests/test_openai_adapter_parity.py tests/test_openai_adapter_edges.py -q
• pytest tests/adapters -q
• ruff check src/foundry/adapters tests/test_openai_adapter_contract.py tests/test_openai_adapter_parity.py tests/test_openai_adapter_edges.py
• mypy src/foundry/adapters
• pytest -q (fails: missing optional dependency pydantic for unrelated IO tests)

Closes #32

https://chatgpt.com/codex/tasks/task_e_68fb01a98ab08322aee133798fb3f068

[github-actions]

Review Brief

Task

• Task Card: Not detected
• Linked Issue: TC-06 — Adapter Layer: Canonical Streaming Integration (V2) #32

Risk

• Level: high
• Changed files: 12

Scope

• tests (4 files)
• src/foundry/adapters (3 files)
• src/foundry/runtime (3 files)
• docs (1 file)
• scripts/ci (1 file)

Coverage

Coverage report not found. Run pytest with --cov to generate coverage.xml.

API changes

Added functions

• foundry.adapters.openai_adapter.monotonic_seq: (*, start: int = 0) -> Callable[[], int]
• foundry.adapters.openai_adapter.stable_ts: (*, origin: datetime = TS_ORIGIN, step: timedelta = TS_STEP) -> Callable[[], datetime]

Added classes

• foundry.adapters.base.AdapterStreamError (methods: no public methods)
• foundry.adapters.base.BaseAdapter (methods: stream)
• foundry.adapters.base.FinalEvent (methods: no public methods)
• foundry.adapters.base.TokenEvent (methods: no public methods)
• foundry.adapters.base.ToolCallEvent (methods: no public methods)
• foundry.adapters.base.ToolResultEvent (methods: no public methods)
• foundry.adapters.openai_adapter.OpenAIAdapter (methods: stream)

Removed classes

• foundry.runtime.loop.AgentRuntime (methods: aclose, closed, on_complete, on_event, on_tool)
• foundry.runtime.loop.SessionTranscript (methods: events, record, replay, states)
• foundry.runtime.state.AgentState (methods: snapshot)

Contracts

No contract tests changed. High-risk change — run pytest tests/contracts for safety.

Notes

• ℹ️ coverage.xml not found; coverage section includes guidance.

[github-actions]

Review Brief

Task

• Task Card: Not detected
• Linked Issue: TC-06 — Adapter Layer: Canonical Streaming Integration (V2) #32

Risk

• Level: high
• Changed files: 12

Scope

• tests (4 files)
• src/foundry/adapters (3 files)
• src/foundry/runtime (3 files)
• docs (1 file)
• scripts/ci (1 file)

Coverage

Coverage report not found. Run pytest with --cov to generate coverage.xml.

API changes

Added functions

• foundry.adapters.openai_adapter.monotonic_seq: (*, start: int = 0) -> Callable[[], int]
• foundry.adapters.openai_adapter.stable_ts: (*, origin: datetime = TS_ORIGIN, step: timedelta = TS_STEP) -> Callable[[], datetime]

Added classes

• foundry.adapters.base.AdapterStreamError (methods: no public methods)
• foundry.adapters.base.BaseAdapter (methods: stream)
• foundry.adapters.base.FinalEvent (methods: no public methods)
• foundry.adapters.base.TokenEvent (methods: no public methods)
• foundry.adapters.base.ToolCallEvent (methods: no public methods)
• foundry.adapters.base.ToolResultEvent (methods: no public methods)
• foundry.adapters.openai_adapter.OpenAIAdapter (methods: stream)

Removed classes

• foundry.runtime.loop.AgentRuntime (methods: aclose, closed, on_complete, on_event, on_tool)
• foundry.runtime.loop.SessionTranscript (methods: events, record, replay, states)
• foundry.runtime.state.AgentState (methods: snapshot)

Contracts

No contract tests changed. High-risk change — run pytest tests/contracts for safety.

Notes

• ℹ️ coverage.xml not found; coverage section includes guidance.