Add VlcPlayer engine and update docs/enums
Introduce the new VlcPlayer live engine: add Engine-VlcPlayer.md and wire VlcPlayer into documentation, enums, settings, caches, logs, publish pipeline, preprocessor symbols, properties, and runtime-dependency pages. Update references/counts from seven→eight engines, include VlcPlayer in EngineType/PropertiesType lists, allowed-engine matrices (Gif/Video), cache and AppData paths, customization/property-panel docs, and publish scripts/docs to include the new project. Documentation clarifies libVLC is bundled (no runtime prompt) and notes hardware-acceleration behavior and GIF handling. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Add mermaid diagrams to architecture and internals docs
Embed mermaid flow/sequence diagrams across multiple documentation pages to visualize multi-process flows and lifecycle behaviour. Files updated: Architecture-Overview.md, Backgroundog-Service.md, Command-Reference.md, Crash-Reporting.md, IPC.md, Lifecycle.md, Undo-Internals.md, Update-Internals.md. Diagrams illustrate who-spawns-whom, Backgroundog lifecycle and data pump, command-bus flow, crash/reporting flow, IPC transports, cold-start sequence, uninstall removal sequence, and update pipeline. Improves developer clarity by providing visual references for existing textual descriptions.