docs: define Autodesk launcher next architecture

architecture/autodesk-launcher/as-is/startup-sequence.md

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+# AS-IS startup sequence
+
+```mermaid
+sequenceDiagram
+  participant U as User
+  participant I as All_Serv_Install
+  participant S as P_Serv_Starter
+  participant B as start_plant_3d.bat
+  participant A as Plant 3D
+  participant L as launcher_starter.lsp
+  participant O as OrthoLoader.dll
+  U->>I: select Plant product/project
+  I->>S: start configured bootstrap
+  S->>S: create _app_netload.lsp; copy LISP
+  S->>B: Process.Start
+  B->>A: launch (details UNKNOWN)
+  Note over A,L: UNKNOWN_BOOTSTRAP: automatic LISP invocation not observed
+  L->>L: rename/load app_netload.lsp
+  L->>O: NETLOAD local OrthoLoader.dll
+  O->>O: read Settings.xml; ._netload ordered modules
+  O->>A: create PluginsOrtho ribbon
+```
+
+The lower sequence is conditional on `launcher_starter.lsp` being started; the initiating AutoCAD configuration is unknown.