Add data-driven procedural dialogue to eve.Dialogue:
- Variables: setVar/getVar*/hasVar/clearVar/clearVars with global and
scene scopes; the scene scope auto-clears when the selected Scene host
changes (polled in update()).
- Conditions: structured tables ({var,op,value} with eq/ne/gt/ge/lt/le/
has/missing, all/any/not, script predicates) + evalCondition().
- Line pools: loadPoolsFromTable() with weight/when/meta/tags, seeded
weighted selection (setRandomSeed), per-pool no-repeat history, and
playLine()/playPool() that resolve {var} interpolation or i18n keys and
auto-apply meta.expression/motion to bound avatars.
- .dnut authoring format compiled by a new C++ parser (DnutParser):
loadPoolsFromDnut(source, path) / loadPoolsFromDnutFile(path); parse
errors surface path:line via getLastPoolsError(). The previous Squirrel
compiler script and its engine wiring are removed.
- Example (examples/dialogue) uses pools.dnut with mood/hour variables,
scene-scope auto-clear demo, and hot reload via eve_asset_reload.
- Tests: C++ unit tests (dialogue_proc.cpp) covering variables,
conditions, pools, selection/dedupe, meta, i18n, scene auto-clear and
the .dnut parser; Squirrel integration test for the script-facing API.
- Docs: design doc updated with the new content model / API / format.
