docs: update architecture doc for inlined polydock libraries

[dan2k3k4]

Updates the architecture documentation to reflect the Polydock libraries now being inlined in the app rather than external Composer packages.

Greptile Summary

This PR updates the architecture documentation to reflect that the Polydock libraries (core, clients, and app implementations) were inlined directly into this repository under app/Polydock/ rather than being consumed as external Composer packages.

• Replaces all freedomtech-hosting/polydock-* package references with paths under app/Polydock/, and updates the interface implementation claims accordingly.
• Expands the previously placeholder "Job Processing Architecture" and "Event System" sections with accurate descriptions of the state machine, lifecycle stages, and Laravel events.
• Corrects the PolydockAppAi class name to PolydockAiApp, matching the actual filename app/Polydock/Apps/Generic/PolydockAiApp.php.

Confidence Score: 5/5

Documentation-only change with no runtime code modified; safe to merge.

All changed content is in a single Markdown documentation file. Key claims were cross-checked against the actual source: PolydockAppInstance does implement PolydockAppInstanceInterface, ProgressToNextStageJob does operate on PolydockAppInstance::$completedStatuses, the branch condition at POST_DEPLOY_COMPLETED matches remoteRegistration || getKeyValue('user-email'), and the upgrade job stubs are confirmed. The PolydockAiApp rename matches the real filename.

No files require special attention.

Important Files Changed

Filename	Overview
docs/ARCHITECTURE/README.md	Documentation-only update replacing external package references with inlined app/Polydock/ paths; claims verified against actual source files.

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