Flips ``RuntimeConfig.discourse_planner`` from ``False`` → ``True``
(the architectural intent the planner was designed for) AND adds a
fast-path early return so single-fact prompts pay no extra cost.
Why the flip
------------
The discourse planner apparatus has been fully wired in the codebase
for some time (``generate.discourse_planner.plan_discourse`` /
``plan_compound_discourse`` / ``render_plan``,
``generate.grounding_accessors.grounding_bundle_for``,
``chat.runtime._maybe_apply_discourse_planner``) but gated off behind
this flag. Investigation surfaced that:
* **Cognition eval (45 cases) is byte-identical OFF vs ON** across
both surface and trace_hash projections — the planner's
downstream ``len(plan.moves) <= 1`` gate correctly returns
``None`` for single-fact prompts, leaving them with the exact
existing pack-grounded surface.
* **NARRATIVE / EXAMPLE / EXPLAIN / PARAGRAPH and compound shapes
visibly lift.** ``"Tell me about memory."`` goes from a one-
fragment disclosure to a 3-sentence grounded discourse.
``"What is truth, and why does it matter?"`` — currently refused
as OOV because the flat classifier sees the polluted subject —
becomes a 6-sentence grounded articulation via the compound
bypass.
* **No quality regression on existing benches.** The full bench
suite (determinism / latency / speedup / versor / convergence /
realizer / teaching-loop / articulation) stays 8/8 PASS with
the flag on.
Why the fast-path
-----------------
Default-on uncovered a perf trap: the gate ran
``grounding_bundle_for(lemma)`` (pack + teaching + cross-pack queries)
AND ``plan_discourse(...)`` on EVERY turn, then discarded the
result when ``len(plan.moves) <= 1``. For BRIEF mode the budget
``_MODE_BUDGETS[BRIEF] = (1, 1)`` guarantees plans of length ≤ 1, so
the downstream gate is guaranteed to reject — pure waste. The
register matrix test runtime went from ~30s → ~14 minutes (28x
slowdown) under the naive default-flip before the fast-path landed.
The new short-circuit:
if mode is BRIEF and not compound.is_compound():
return None
skips the bundle query + plan run entirely for the common case.
Compound prompts still flow through (they get auto-upgraded BRIEF
→ EXPLAIN on the line above). Empirical post-fast-path
measurement on a 45-case eval (workers=1):
OFF: 23.31s (1.93 turns/sec)
ON : 17.74s (2.54 turns/sec)
slowdown : 0.76x (flag-ON is actually 24% FASTER — the bundle
work the OFF path also touches downstream is
short-circuited cleanly when not needed)
surface byte-equal: True
trace_hash byte-equal: True
Test updates
------------
* ``test_discourse_planner_render.py`` — invert
``test_default_runtime_config_has_flag_off`` →
``test_default_runtime_config_has_flag_on`` and rename
``test_flag_off_default_unchanged`` →
``test_flag_off_explicit_path_unchanged`` (the OFF path is still
a load-bearing invariant, just no longer the default).
* ``test_narrative_example_intents.py`` — three tests that assert
composer-level provenance tags (``narrative-grounded``,
``example-grounded``, ``relations_chains_v1``) now explicitly
set ``RuntimeConfig(discourse_planner=False)`` so they continue
to exercise the underlying composer. The runtime-level
multi-sentence behavior is pinned separately by
``tests/test_articulation_demo.py``.
Verified
--------
cognition eval (45 cases) OFF ≡ ON byte-identical
pytest tests/test_discourse_planner_* 132/132 pass
pytest tests/test_articulation_demo.py all claims supported
pytest tests/test_narrative_example_intents.py pass
pytest tests/test_runtime_config.py pass
core test --suite smoke 67/67 pass
core test --suite runtime 19/19 pass
core test --suite packs 6/6 pass
Live demo (default config):
"What is knowledge?" → single sentence (BRIEF, fast-path)
"Tell me about memory." → 3 grounded sentences
"What is truth, and why does
it matter?" → 6 grounded sentences (was: OOV)
"Explain truth." → 3 grounded sentences
63ffd88595