docs: update spectrum-ts documentation for v1.8.0

[photon-action-bot]

Documentation Update: spectrum-ts v1.8.0

This PR updates documentation for spectrum-ts based on the v1.8.0 release.

Release Notes

New Features

• Added opt-in OpenTelemetry support with telemetry: true, so apps can trace Spectrum startup, provider setup, message receive/send/get flows, space resolution, and custom events. ✨
• Telemetry now includes useful Spectrum context like provider name, space ID, content type, sender kind, and safe identifier metadata.

Bug Fixes

• Fixed package publishing so prepack runs the full build, making sure generated files and package assets are ready before release.

Improvement

• Added package preparation that stamps the SDK version into the build and copies the README and LICENSE into the package automatically.
• Unsupported platform/content warnings are now emitted as structured telemetry logs, making production issues easier to diagnose.

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Version: 1.8.0

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🤖 This PR was auto-generated by Claude Code via the update-docs action in buildspace.

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