Add posture-expansion templates and pre-bind expansion stage with derived-graph provenance

[danielbdyer]

Motivation

• Provide a canonical, reviewable way to express scenario expansion rules (target screen, baseline posture, override partitions, include/exclude, and expansion limits) so derived test variants can be generated deterministically from approved artifacts.
• Keep generated variants disposable and provenance-rich so derivations remain auditable and graphable without making expanded scenarios a new canonical truth.
• Surface common validation failure modes (missing posture partition, unknown element, non-input action) earlier in the pipeline to improve correctness and diagnostics.
• Make expansion an explicit, pre-bind stage so the binding and downstream graph/type generation stages operate over a stable, deterministic set of derived variants.

Description

• Introduced a canonical template artifact format under scenarios/templates/ (example: policy-search.posture-expansion.yaml) that encodes id, scenarioAdoIds, and rules with screen, baseline, overrides, include/exclude, and maxExpansions.
• Added domain types for templates and expanded outputs (ScenarioTemplateArtifact, ExpandedScenarioSet, ExpandedScenarioVariant, PostureExpansionRule) and extended GraphNodeKind/GraphEdgeKind to include template and derived-from-template kinds.
• Implemented lib/domain/posture-expansion.ts containing expandScenarioPostures which consumes Scenario, ScreenElements, and ScreenPostures and emits deterministic expanded variants with stable ordering (by element id) and stable variant ids (fingerprinted via sha256(stableStringify(...))).
• Added lib/application/expand.ts to run expansion as a pre-bind stage, validate templates via validateScenarioTemplateArtifact and validateTemplateExpansionContext, and persist derived expansions under .tesseract/bound/expanded/*.expanded.json (derived space; not canonical).
• Wired expansion into orchestration by calling expandScenarioTemplates in the compile workflow (lib/application/compile.ts) prior to binding, and exposed the expanded result in compile outputs.
• Extended validation in lib/domain/validation.ts to parse/validate template artifacts and to produce semantic diagnostics for expansion context issues (missing posture partitions, unknown elements, non-input actions).
• Extended derived-graph construction and ids (lib/domain/derived-graph.ts, lib/domain/ids.ts, lib/application/graph.ts) to include template nodes and scenario-variant nodes and to emit derived-from-template edges so provenance from template -> generated variant is represented in the graph; template and expanded scenarios are included in graph input fingerprints for deterministic caching.
• Added law-style tests and integration checks: deterministic expansion unit test (tests/domain.spec.ts) and refresh-level deterministic expanded-output test (tests/compiler.spec.ts).

Testing

• Built the project with npm run build (TypeScript compilation) and then ran the test suites:
  • node ./node_modules/@playwright/test/cli.js test tests/domain.spec.ts tests/compiler.spec.ts
• Result: all tests passed (17 passed).

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Codex Task