[WIP] Restructure marcj/deepkit into d7

[Copilot]

Restructure deepkit into d7

This PR renames the framework from "deepkit" to "d7" due to trademark issues (as mentioned in README: "Formerly Deepkit — renamed after European Union 'no genuine use' ruling").

Progress:

• Understand the scope of the rename (packages, documentation, code)
• Rename package scopes from @deepkit/* to @d7/*
• Update repository URLs from deepkit/deepkit-framework to marcj/d7
• Update README and documentation
• Update code references and imports in TypeScript files
• Update configuration files (package.json, lerna.json, etc.)
• Test the build and ensure everything works
• Fix any remaining references
• Update website content if needed

Changes Made:

• Renamed all @deepkit/* packages to @d7/* (88 packages)
• Updated repository URLs from deepkit/deepkit-framework to marcj/d7
• Updated documentation URLs from deepkit.io to d7.io
• Updated npm init command from @deepkit/app to @d7/app
• Updated text references from "Deepkit" to "D7" in descriptions
• Fixed example app names and community package references

Original prompt

restructure marcj/deepkit into d7

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