This PR implements the **OPC UA Device Integration (DI, OPC 10000-100)**
companion-spec library trio (`Opc.Ua.Di` / `Opc.Ua.Di.Server` /
`Opc.Ua.Di.Client`) plus a worked example
(`Applications/MinimalPumpServer`) demonstrating the OPC 40223 Pumps
companion specification end-to-end with full simulation. It also closes
11 fluent-API gaps in `Opc.Ua.Server.Fluent`, three source-generator
bugs, integrates the DI layer into the unified `services.AddOpcUa()`
Microsoft.Extensions DI hosting pattern, and adds 250+ new tests.
**Worked example — `Applications/MinimalPumpServer/`**
- AOT-compatible console host using `Host.CreateApplicationBuilder` +
`AddOpcUa()`.
- `PumpNodeManager` inherits from `DiNodeManager`; multi-namespace (DI +
Machinery + Pumps) via runtime NodeSet2 loading and
`ModelLoaderBuilder`.
- Demonstrates declarative second-pump creation via
`.ConfigureDevicesFor<PumpNodeManager>(...)` and software-package
seeding from the same configurator.
- Full simulation: pressure, temperatures, power, flow, efficiency,
level, cavitation/overheat fault injection, alarm setup, NAMUR-style
supervision.
**Documentation**
- `Docs/Opc.Ua.Di/` — README, DeviceBuilder, Hosting, LockService,
SoftwareUpdate, ClientHelpers (6 new developer guides).
- `Docs/Opc.Ua.Di/ComplianceMatrix.md` — every DI declaration mapped to
In-v1 / Generated / Deferred / Excluded.
- `Docs/CompanionSpecLibraries.md` — packaging guide for new
companion-spec libraries.
- `Docs/FluentApiGaps.md` — historical record of G1–G11.
- `Docs/SourceGeneratedNodeManagers.md` updated for richer node
managers.
- `Docs/plans/StateMachineBuilder.md` — deferred state-machine builder
design.
Marc Schier