Step 5 of the discourse-planner sequencing. Closes the chain:
classify_intent + classify_response_mode
-> grounding_bundle_for(subject)
-> plan_discourse(intent, mode, bundle)
-> render_plan(plan)
-> response_surface
Adds RuntimeConfig.discourse_planner (default False). When True, the
runtime — after the warm pack/teaching-grounded surface is set —
classifies the response mode, assembles a GroundingBundle from the
ADR-style accessors, builds a DiscoursePlan, and replaces the warm
surface with the deterministic multi-clause rendering whenever the
plan has more than one move.
Gating discipline:
* Engages only on warm_grounding_source in {"pack", "teaching"} so
vault/none turns and the discovery-signal CAUSE/VERIFICATION
disclosure are preserved exactly.
* BRIEF mode always collapses to a single ANCHOR move, so flag-on
with BRIEF intent is byte-identical to flag-off.
* Empty bundles produce empty plans; the runtime falls through to
the existing warm surface untouched.
Adds render_plan(plan) to generate/discourse_planner.py — a pure,
deterministic multi-clause renderer with fixed canonical connectives:
ANCHOR : capitalized opening sentence
SUPPORT : "Furthermore, ..."
RELATION : "In turn, ..."
TRANSITION: "Consequently, ..."
CLOSURE : skipped when fact is None
Every visible token is a verbatim pack lexicon entry, gloss, or
reviewed teaching chain string — no synthesis.
13 new tests pin:
* render_plan empty/brief/paragraph shape
* canonical connectives present in paragraph rendering
* deterministic + verbatim-fact invariants
* RuntimeConfig.discourse_planner defaults False
* Flag-off surface has no planner connectives
* Flag-on lifts produce structurally well-formed multi-sentence
output on grounded substrate
Lift measurement (multi_sentence_response public/v1, 15 cases):
* flag off: multi=0.40, connective=0.50, grounded=0.40
* flag on : multi=0.40, connective=0.60, grounded=0.40
-> connective_present_rate +10pp; multi-sentence count flat
because the existing narrative composer's literal "." chars in
tags like "cognition.truth" already trigger sentence splits in
the lane regex. Real lift is form quality: e.g. "Tell me about
truth" now renders as "Truth is a claim or state grounded by
evidence and coherent judgment. Furthermore, truth belongs to
cognition.truth. In turn, truth grounds knowledge." instead of
the prior provenance-laden narrative surface.
Critical gates (all green):
* flag off: cognition eval byte-identical
- public 100/100/91.7/100, holdout 100/100/83.3/100
* smoke suite 67/67
* conversational_thread_coherence: 3 unwanted placeholders flag off
and flag on (no regression)
* planner JSON byte-stable across calls (contract tests)
* grounding source order preserved (sidecar tests)
