Adds the typed ChannelDrm model (shared interfaces) and a KODIPROP
post-processing step in createPlaylistObject() — the single funnel for all
four playlist import paths. Parses inputstream.adaptive.license_type,
license_key and drm_legacy; ClearKey keys accepted as kid:key hex pairs,
W3C ClearKey license JSON, or a plain kid→key JSON map. Unsupported license
types (Widevine/PlayReady/license URLs) are preserved with supported=false
so playback can surface a DRM diagnostic instead of failing silently.
Also adds isDashStreamUrl/isDashChannel helpers for DASH routing.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
