Audit and refactor docs around SQMeter ASCOM Alpaca bridge

[DeanJ87]

Summary

• Reframes the project documentation around SQMeter ASCOM Alpaca / bridge terminology. The README title is now SQMeter ASCOM Alpaca and includes a clear "Project scope and naming" table distinguishing the bridge from the two Alpaca devices it exposes (SQMeter SafetyMonitor and SQMeter ObservingConditions).
• Clarifies SafetyMonitor and ObservingConditions as separate Alpaca devices exposed by one service, documented in a new docs/nina.md.
• Updates configuration, installer, upgrade, N.I.N.A., discovery, diagnostics, and troubleshooting docs to match current behaviour, split across new files: docs/configuration.md, docs/windows-service.md, docs/upgrading.md, docs/troubleshooting.md.
• Fixes stale configureddevices example in docs/nina-alpaca-discovery.md to show both devices, and updates bridge-vs-device naming throughout.
• Removes stale "future tray icon" promise from the upgrading section of README.
• Updates web dashboard and setup page <title> and <h1> to SQMeter ASCOM Alpaca.
• Updates PRIVACY.md project name.

Validation

• Documentation review
• go test ./... — all packages pass

Notes

• This PR does not rename the repository, binary, service, installer, or Go module.
• The binary and module remain sqmeter-alpaca-safetymonitor; the service display name remains SQMeter Alpaca SafetyMonitor. A note in the README project-scope section documents this.

Follow-up recommendations

• Repository rename: Consider renaming DeanJ87/SQMeter-Safety-Monitor → DeanJ87/SQMeter-ASCOM-Alpaca on GitHub. Requires updating badge URLs, ReleasesURL in internal/config/paths.go, installer AppURL, and any external links.
• Binary / service name: Consider renaming the binary to sqmeter-ascom-alpaca and the Windows service display name from SQMeter Alpaca SafetyMonitor to SQMeter ASCOM Alpaca. Requires updating go.mod module path, all import paths, CI workflow build targets, GoReleaser config, Inno Setup ExeName / SetupBase, and service Name/DisplayName in main.go.
• Go module path: module sqmeter-alpaca-safetymonitor in go.mod should become sqmeter-ascom-alpaca as part of the binary rename above.
• AppDataDir / ProgramData path: AppDataDirName = "SQMeter SafetyMonitor" in internal/config/paths.go and #define AppDataDir "SQMeter SafetyMonitor" in installer/setup.iss could be updated to a new name, but this is a migration-sensitive change — existing installs would lose their config path. Defer until a migration path is implemented.