feat(transition): Transition Reasoning v0 (RS-005) — Transition Planning Engine

Second reasoning mode, scope per user: the engine owns the INFORMATION GAPS, not the
questions. assess_transition(context, target_requirements, company_profile) emits
ranked TransitionQuestionRequest {capability, control, reason, question_intent,
expected_evidence, priority, information_gain} -- NOT rendered question text. Rendering
(intent+subject->sentence) is a separate swappable layer (RS-005.1), not here.

Consumes the Company Capability Profile (2A) as "have" + injected TargetRequirement
(Execution-owned placeholder) as "required" -- no required-capability data in product
code (EMPTY_REQUIREMENTS, mocks only in tests). A certification-derived capability is
probably_covered (Welt 1) -> a confirmation request, never already_covered/"erfuellt".
Deterministic, computed-not-stored, no percentages.

Activates 2A/2C/RCI (first consumer of the Company profile). Freeze-respecting: additive
package, no new graph/base class/meta-model class. 9 tests, mypy --strict clean, LOC ok.
No endpoint/UI/RAG; question rendering deliberately deferred to RS-005.1.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend-compliance/compliance/transition_reasoning/__init__.py

@@ -0,0 +1,42 @@
+"""Transition Reasoning v0 (RS-005) — the Transition Planning Engine.
+
+Answers „Was muss ich noch wissen, um vom Ausgangs- in den regulatorischen
+Zielzustand zu kommen?". Owns the **information gaps** (`TransitionQuestionRequest`),
+NOT the rendered questions (rendering = separate RS-005.1 layer).
+
+Consumes the Company Capability Profile (2A) as „have" + injected `TargetRequirement`
+(Execution-owned placeholder) as „required". Spec: docs-src/architecture/transition-reasoning-spec-v1.md.
+"""
+
+from __future__ import annotations
+
+from .engine import EMPTY_REQUIREMENTS, assess_transition
+from .schemas import (
+    CapabilityCoverage,
+    CoverageStatus,
+    InformationGain,
+    RequestPriority,
+    TargetRequirement,
+    TargetType,
+    TransitionAssessment,
+    TransitionContext,
+    TransitionGoal,
+    TransitionQuestionRequest,
+    TransitionSummary,
+)
+
+__all__ = [
+    "assess_transition",
+    "EMPTY_REQUIREMENTS",
+    "TransitionContext",
+    "TransitionGoal",
+    "TargetType",
+    "TargetRequirement",
+    "TransitionQuestionRequest",
+    "CapabilityCoverage",
+    "CoverageStatus",
+    "RequestPriority",
+    "InformationGain",
+    "TransitionSummary",
+    "TransitionAssessment",
+]