Delete bundled frontends/qt6/qmllib QML libraries (Material, MetaBuilder, dbal, etc.) now provided from the extracted qml/qt6 tree. Update frontends/qt6/generate_cmake.py to also scan ../../qml/qt6 (relative to the root) and include those files (using relative paths) when generating the list. Also apply small updates to a few qml/MetaBuilder files (CSmtpServerForm.qml, CWorkflowTestPanel.qml, ThemeColorTokens.qml, ThemeTypography.qml) to align with the extraction.
Add a large set of QML components (qml/Material, qml/MetaBuilder, qml/dbal) and a QmlComponents symlink for local development; migrate many frontends/qt6 files into qml/qt6. Replace the email client bootloader with a self-contained demo UI using FakeMUI primitives (MailboxLayout, ThreadList, EmailHeader, ComposeWindow), demo data, handlers, and new folder-navigation styles in globals.css. Update several QML component APIs to new signal/handler names (e.g. selectAllChanged→selectAllToggled, pageChanged→pageRequested, *Changed→*Edited) to standardize events. Add find_config_files() to frontends/qt6/generate_cmake.py to include config JS/JSON in QML/files and resources. Also add /frontends/qt6/_build to .gitignore.