Step 2 of the discourse-planner sequencing: add the presentation-depth
axis ResponseMode (brief / explain / walkthrough / paragraph / example)
as a sibling to IntentTag in generate/intent.py, with a deterministic
rule-based classify_response_mode classifier next to classify_intent.
ResponseMode previously lived in generate/discourse_planner.py; moved
to generate/intent.py so the dependency is one-way (planner imports
from intent, never reverse). discourse_planner.py now re-exports.
Additive-only invariant preserved:
* DialogueIntent fields unchanged (tag/subject/secondary_subject/
relation/frame). No equality breakage anywhere downstream.
* classify_intent branches untouched.
* Callers compose (classify_intent(t), classify_response_mode(t))
rather than threading mode through DialogueIntent.
41 new tests pin: placement (canonical home + re-export identity),
classifier behavior (parametrized over 25 prompts), priority ordering
(paragraph > explain, walkthrough > explain), purity (no clock/env/
filesystem), classify_intent invariance (definition / narrative /
example / cause / verification representative cases), and orthogonality
(intent and mode compose, neither shadows the other).
Verification:
* 96/96 existing intent tests pass.
* 69/69 new contract + characterization + classifier tests pass.
* smoke suite 67/67.
* cognition eval byte-identical: public 100/100/91.7/100,
holdout 100/100/83.3/100.
Contract-only landing for the typed multi-move discourse layer that
will sit between grounding and graph construction:
DialogueIntent + ResponseMode + GroundingBundle
-> DiscoursePlan
-> PropositionGraph
-> ArticulationTarget
-> RealizedPlan
Adds frozen dataclasses (ResponseMode, FactSource, GroundedFact,
GroundingBundle, DiscourseMoveKind, DiscourseMove, DiscoursePlan),
canonical sort + as_dict + to_json serialization (sorted keys,
no-whitespace separators), and the pure plan_discourse signature
(raises NotImplementedError; move-selection rules deferred).
23 contract tests pin the determinism invariants required before
DiscoursePlan can be folded into compute_trace_hash in a follow-up
ADR: frozen-dataclass equality, canonical pack<teaching<vault<operator
ordering, byte-stable to_json across calls and equal plans, JSON
round-trip stability, and signature purity (no chat.* imports, no
clock/env/filesystem reads).
No runtime wiring; smoke suite 67/67; cognition eval byte-identical
(public 100/100/91.7/100, holdout 100/100/83.3/100).
