libmoq: C ABI catch-up with the moq-ffi surface

[kixelated]

The libmoq C ABI (rs/libmoq/src/api.rs) has fallen well behind moq-ffi. All of these are additive (new symbols), so none block the dev->main merge, but the backlog is getting long:

• Subscription options: moq_consume_track takes no options; no priority/ordered/stale/group-range equivalent of MoqSubscription, and no mid-stream update.
• Track info on publish: moq_publish_track cannot set timescale/priority/ordered/cache (no MoqTrackInfo equivalent).
• Fetch: no fetch_group, and no dynamic group serving (moq-ffi gains these in feat(moq-ffi): expose group fetch API #2142; mirror the shape).
• Dynamic track/broadcast serving: no requested_track/requested_broadcast path at all.
• abort with error code: only clean close/finish exists; no abort(code) for tracks/groups.
• Server / two-phase accept: no server-side API (moq-ffi has MoqServer/MoqRequest with the SETUP path); C embedders cannot accept sessions.
• Client TLS knobs: roots/system-roots/fingerprints/disable-verify are env-only; moq-ffi exposes them as options.
• Datagrams: tracked with the moq-ffi datagram issue; mirror whatever lands there.
• Raw-frame timestamps: raw consume reports timestamp_us = 0; tracked with the raw-frame timestamps issue.

Suggest splitting off pieces as they're picked up rather than one mega-PR. Each addition also touches cpp/obs consumers only if used, plus doc/lib/c per the Cross-Package Sync table.

(Written by Claude Fable 5)

[coderabbitai]

🔗 Related PRs

#645 - Add more compatibility for draft 14 [closed]
#1036 - Tweak the API to revert some breaking changes. [closed]
#1068 - Add comprehensive FFI integration tests for libmoq broadcast [closed]
#1071 - Uniffi async objects [closed]
#1100 - Fix moq-ffi CI for iOS and aarch64 Linux Python wheels [closed]
#1792 - fix(libmoq): declare the full Windows system-lib set for C consumers [merged]
#1875 - fix: link macOS CoreServices for the bundled notify/FSEvents backend [merged]
#2046 - [codex] Future-proof moq-net metadata structs [merged]

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