feat: scripts/cascade_for_combo.py — per-combo cascade stats - #48

…ark-runs

Reconciles this branch's DEV-1555 / DEV-1561 + CR r1 unification work
with PR #46 (DEV-1550 SLayer compact-by-default), PR #48
(cascade_for_combo), PR #50 (query-syntax-rejection analysis), and
DEV-1545 + DEV-1546 prompt additions on origin/main.

Conflict resolutions:

* ``_shared_otf_prompts.py`` — replaced HEAD's V1 helper section with
  origin/main's (it carries the new ``_DEDUP_VS_RAW_ROWS``,
  ``_TABLE_SET_PROBE``, ``_GRADER_ZERO_VS_ONE_DIAGNOSTIC``,
  ``_SLAYER_TOOLS_BLOCK`` etc. plus DEV-1550 ModelColumn / memory drill-
  in paragraphs), restored our ``_AFTER_REJECTED_DISCIPLINE`` (DEV-1555
  stage-2), and kept our four ``*_V0`` snapshots appended at the
  bottom. Stripped lingering ``query_nested`` mentions from the V1
  helpers so the unified-tool contract holds on both sides.

* ``claude_sdk/agent.py`` — kept the unified ``query`` schema
  (``source_model`` + projection fields OR ``queries`` array;
  ``required: []``) and the runtime ``source_model XOR queries`` gate.
  The handler now builds the SlayerQuery JSON internally and forwards
  it to origin/main's DEV-1546 ``query_impl(query_json: str, …)`` for
  single-stage, or to ``query_nested_impl(queries=…)`` for the
  nested-DAG form — matching ``submit_query``'s pattern. Picked up
  origin/main's ``distinct_dimension_values`` field as an additional
  schema property so the DEV-1546 dim-only auto-dedup opt-out stays
  reachable through the unified shape.

* ``eval/autopsy.py`` — combined origin/main's 2-attempt corrective-
  retry loop (sends Pydantic validation errors back as a
  ``tool_result`` so the model self-fixes the archeology_10 regression)
  with our DEV-1555 model-aware client (``_build_anthropic_client(model)``
  + ``requires_thinking(model)`` thinking mode + auto tool_choice for
  Moonshot/Kimi) and the JSON-text fallback for third-party endpoints
  that don't honor forced tool_choice. The retry only fires when the
  model used the tool (the JSON-text-fallback path has no
  tool_use_id to bind the corrective ``tool_result`` to).

* ``run.py._per_task_timeout_s`` — origin/main flipped the default to
  ``_DEFAULT_PER_TASK_TIMEOUT_S = 0.0`` (no cap). Adjusted our DEV-1555
  grace logic so the runaway grace is only added when the operator
  explicitly opted in to a positive cap — the default-uncapped contract
  now holds.

* V0 prompts kept as thin re-exports from ``_shared_otf_prompts.V0``
  snapshots (origin/main had touched ``claude_sdk_otf*/prompts.py``
  with DEV-1545/1550 helper composition, but our side reduced those
  files to one-line re-exports so the V0 snapshot is the single source
  of truth for the v0 surface).

* ``test_shared_otf_prompts.py`` — re-baselined the V1 SHA pins to
  ``3fa05ac2…``/``65b8eb05…`` → final post-cleanse
  ``e671aea3…``/``a3fd695c…`` after stripping lingering ``query_nested``
  mentions from the merged V1 helpers.

* ``test_dev1534_query_wrapper.py`` — rewrote the schema pin to match
  the unified shape (``source_model``, ``queries``, ``required: []``);
  the prior DEV-1546 ``query_json``-only pin is superseded.

* ``test_dev1546_distinct_dim_values.py`` — repointed the dedup
  composition tests at the ``SLAYER_OTF_*_V0`` snapshots (where the
  full ``_DEDUP_VS_RAW_ROWS`` body is inlined byte-for-byte); the v1
  prompts teach the same guidance in a shorter form not assembled via
  the live constant. Rewrote the query-tool-schema test to assert the
  unified-shape surface.

* ``test_dev1555_query_unified_schema.py`` — updated the mock
  ``query_impl`` to take ``query_json: str`` positional + kwargs
  (matches DEV-1546's signature) and parse it to verify the wrapper
  built the right SlayerQuery dict.

Full non-integration suite: 3212 passed, 94 skipped, 50 deselected, 0
failed.