Drop null keys from every licence, server and export source, not only Widevine. dl now finds remote sessions and imports through ServerKeySource instead of private fields.
The export writes mediaexport content_periods per manifest; an import that re-fetches the MPD (no saved snapshot) drops the periods a service filtered.
--export writes the mediaexport format with DRM, content keys and manifests at title level, and unshackle's own track dicts under x-unshackle. unshackle import reads mediaexport, unidl v1 and unshackle v2 through the shared reader, applies the export's request headers to the import session, and rebuilds DRM from the title-level pool. mediaexport is a git dependency on unshackle-dl/mediaexport.
unshackle's DASH parser only recognised Widevine and PlayReady ContentProtection, so services using W3C EME ClearKey had to fake a Widevine object and monkey-patch get_content_keys. Add a first-class ClearKeyCENC DRM type so services just implement a license callback.
- ClearKeyCENC (core/drm/clearkey_cenc.py): KID-based, no CDM/PSSH; builds the W3C JSON license request (unpadded base64url), parses the JWK Set response (dict/str/bytes), falls back to POSTing the manifest Laurl when the service returns None, decrypts via the same shaka/ mp4decrypt CENC path as Widevine
- DASH.get_drm emits ClearKeyCENC for scheme e2719d58-...; KID from own or sibling mp4protection cenc:default_KID, Laurl across dashif/legacy/ bare namespaces
- track.download dispatches prepare_drm for ClearKeyCENC; dl.prepare_drm gains a clearkey branch (cache/vault lookup, license-failure tolerated when content_keys pre-populated, vault push, export)
- Service.get_clearkey_license base callback (default None -> Laurl); drm_from_dict reconstructs ClearKeyCENC for export/import round-trip
- EXAMPLE service + config demo the callback
- Tests: tests/core/test_clearkey_cenc.py and an export round-trip case
- Docs: DRM_CONFIG.md ClearKey section
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