Phase 0: Repository-Initialisierung nach Bauplan v1.2

- Struktur gemäß §8 (Eigentumsgrenzen), PLAN.md als normative Basis
- Pflichtdokumente: STATUS.md, ERRORS.md, TEST_REPORT.md, CHANGELOG.md, ADRs
- ADR-0001 Python 3.13-Pin, ADR-0002 GStreamer 1.28.6-Pin (Windows),
  ADR-0003 IPC TCP+MessagePack v1
- Kernpakete: hms_protocol, hms_domain, hms_parameter, hms_artnet,
  hms_adaptive, hms_capabilities, hms_plugin_sdk
- Renderer-Spike: D3D11-Primärpfad + Dev-GL-Pfad (§36 Nr. 4-5)
- Control Core: FastAPI REST + WebSocket (§36 Nr. 9)
- Beispielplugins: Passthrough + Gaussian Blur (3 Adaptive-Quality-
  Varianten, HLSL/GLSL/GLES)
- Tools: Art-Net-Emulator, Fixture-Generator (Master32/Layer64-CSV),
  Capability-Probe
- JSON-Schemas: IPC, Plugin, Projekt, Cluster
- 121 Unit-/Integrationstests grün, Ruff grün

Gate 0 bleibt offen: Hardwaremessungen nur auf echter Windows-Referenz-
hardware gültig (§29.7, §33).

packages/parameter_engine/hms_parameter/paths.py

@@ -0,0 +1,49 @@
+"""Stabile Parameterpfade (PLAN.md §10.2).
+
+Pfade werden niemals aus sichtbaren Namen gebildet; alle Teile sind UUIDs
+oder feste Schlüsselwörter.
+"""
+
+from __future__ import annotations
+
+import uuid
+
+_ALLOWED_ROOTS = {"composition", "output", "cluster", "master"}
+
+
+def _is_uuid(value: str) -> bool:
+    try:
+        uuid.UUID(value)
+        return True
+    except (ValueError, AttributeError):
+        return False
+
+
+def validate_parameter_path(path: str) -> bool:
+    """True, wenn der Pfad dem Muster §10.2 entspricht."""
+    if not path or path.startswith("/") or "\\" in path or ".." in path:
+        return False
+    parts = path.split("/")
+    root = parts[0]
+    if root not in _ALLOWED_ROOTS:
+        return False
+    if root == "master":
+        return len(parts) == 2 and parts[1] != ""
+    if root in {"composition", "output"}:
+        if len(parts) < 3:
+            return False
+        if not _is_uuid(parts[1]):
+            return False
+        return all(p != "" for p in parts[2:])
+    # cluster: cluster/group/{uuid}/... oder cluster/node/{uuid}/...
+    if len(parts) >= 3 and parts[1] in {"group", "node"} and _is_uuid(parts[2]):
+        return all(p != "" for p in parts[3:])
+    return False
+
+
+def layer_opacity_path(composition_id: str, layer_id: str) -> str:
+    return f"composition/{composition_id}/layer/{layer_id}/opacity"
+
+
+def master_intensity_path() -> str:
+    return "master/intensity"