docs: define Autodesk launcher next architecture

architecture/autodesk-launcher/target/package-manifest.md

@@ -0,0 +1,26 @@
+# Package manifest
+
+```json
+{
+  "schemaVersion": 1,
+  "packageId": "P_Rec_Annot",
+  "version": "2026.1.0",
+  "product": "Plant3D",
+  "productYear": 2026,
+  "architecture": "x64",
+  "minimumLauncherVersion": "1.0.0",
+  "compatibleAutoCadSeries": ["R25.1"],
+  "requiredRuntime": ".NET 8",
+  "entryAssembly": "PRecAnnot.Plant3D2026.dll",
+  "files": [{ "path": "PRecAnnot.Plant3D2026.dll", "length": 0, "sha256": "<64 hex>" }],
+  "dependencies": [],
+  "optionalResources": [],
+  "rolloutChannel": "pilot",
+  "disabled": false,
+  "rollbackSafe": true,
+  "releaseNotesReference": "relative-release-notes.md",
+  "startup": { "type": "netload", "command": "PHP_REC_ANNOT" }
+}
+```
+
+Validation rejects absolute/traversal/duplicate paths, missing entry assembly, incompatible product/year/architecture, and Autodesk/Plant managed assemblies (`AcMgd`, `AcDbMgd`, `AcCoreMgd`, `AdWindows`, `PnP*`, `Autodesk.ProcessPower*`). No absolute paths belong in a manifest.