Summary

Two Python-only dagster-rocky opt-in features, bundled into one
coordinated release. Default behaviour is unchanged on upgrade for
both — every existing user gets the current buffered/streaming
execution path and the current tolerant doctor behaviour with no
config change required.

FR-001 — RockyComponent.execution_mode: Literal["streaming", "pipes"]

The component-backed multi-asset now supports the Dagster Pipes
protocol as a first-class execution mode. When execution_mode is
set to "pipes", each rocky run invocation goes through
RockyResource.run_pipes and the engine emits
MaterializationEvent / AssetCheckEvaluation entries directly
over the Pipes wire. The buffered _emit_results JSON
post-processing path is skipped in this mode — Pipes becomes the
single source of truth for run events (no double-emit).

Asset-key translation and subset filtering happen at the reader
layer via a new RockyPipesMessageReader: a subclass of
PipesTempFileMessageReader that wraps the handler with a small
proxy. The proxy rewrites the wire asset_key (a slash-joined path
of [source_type, *components, table]) to the Dagster key the
component declared via its translator, and drops events whose
resolved key is outside the subset selection.

Opt-in per-component:

type: dagster_rocky.RockyComponent
attributes:
  execution_mode: pipes

FR-006 — RockyResource.strict_doctor + strict_doctor_checks

Opt-in strict rocky doctor gate at resource startup via
setup_for_execution. Tri-state surface via two fields:

Warnings (non-critical severities) never raise regardless of the
list. Critical-but-not-listed checks are surfaced via
context.log.warning so operators still see them. Both fields
pass through from RockyComponent to the constructed resource.

Opt-in per-component:

type: dagster_rocky.RockyComponent
attributes:
  strict_doctor: true
  strict_doctor_checks: [state_rw]

Design decisions

• Custom PipesMessageReader subclass, not post-filter.
  Translation + filtering happen at the reader layer so events for
  unselected tables never reach Dagster's handler in the first
  place. The interception point is private
  (PipesFileMessageReader._reader_thread calls
  handler.handle_message); if that contract shifts, the dagster
  bump in CI will surface the breakage before release.
• Two-field strictness surface (bool + list[str]). The FR
  doc's optimistic Literal["none", "all"] | list[str] shape
  doesn't round-trip through Dagster's Pydantic config serializer
  (DagsterInvalidPythonicConfigDefinitionError on Union[list, Literal]). Two fields cover the same three semantic cases
  cleanly and type-check.
• Contract checks still sourced from compile diagnostics in
  pipes mode. Contract violations are a build-time signal the
  Pipes wire doesn't carry, so the component keeps emitting them
  post-run in both execution modes.
• run_pipes only wraps the client when translation/filter
  kwargs are passed. Users calling run_pipes directly (not via
  RockyComponent) get the unchanged canonical Dagster Pipes path.

Test plan

• tests/test_pipes_mode.py — 17 new tests covering:
  • Handler-proxy asset-key translation for materializations and
    check events.
  • include_keys filtering at the handler layer.
  • Non-asset messages (log, opened, closed) pass through
    untouched.
  • Malformed asset_key payloads forwarded to the inner handler
    for validation.
  • report_pipes_framework_exception delegation via __getattr__
    (private-API safety net).
  • run_pipes kwarg plumbing: custom reader only when
    asset_key_fn or include_keys is supplied; caller-supplied
    client wins.
  • RockyComponent.execution_mode default is "streaming".
  • _run_filters_pipes builds an asset_key_fn from the group's
    rocky_key_to_dagster_key map, with last-segment fallback for
    drift events.
• tests/test_strict_doctor.py — 13 new tests covering:
  • Disabled mode (default) skips doctor entirely; a broken binary
    is inert.
  • strict_doctor=True + empty list fails on any critical.
  • Allowlist matches: only listed critical checks raise;
    non-listed critical checks surface as warnings.
  • Warning severity never fails (even when listed; even under
    fail-on-any).
  • Binary failures under strict mode wrap into a startup
    dg.Failure.
  • RockyComponent forwards both fields to the resource factory.
• uv run pytest -q → 342 passed (up from 312; 30 new, 0
  regressions).
• uv run ruff check src/ tests/ → clean.
• uv run ruff format --check src/ tests/ → clean.
• No engine-side changes; no codegen regen; no fixture refresh
  needed.

Wave 2 follow-up

RockyResource.state_health() (FR-003) — programmatic state-backend
health probe — ships separately once this lands.