quest: datagrams are live-only, capture by default; drop hls-linger

quest/m1/README.md

@@ -50,17 +50,19 @@ transport, benchmark tooling); worktrees isolate commits, not semantics.
 - [TS PSI reassembly](/quest/m1/ts-psi-reassembly.md) - `import ts` reads a PAT or PMT that spans packets or follows a nonzero pointer_field instead of aborting, and one corrupted section costs a repetition and a counted `CRC_error`, not the import
 - [Same-hop importers](/quest/m1/hop-aligned-import.md) - importers sharing a `--hop` and fed one stream publish identical groups and timestamps, so failover survives
 - [Capture control](/quest/m1/capture-control.md) - on dev, `encode::Capture` replaces `CaptureOptions` without a `clock` field (it reads the catalog's), an unsupported `cut()` errors, and dropping the last `Control` cancels in-flight opens
+- [Capture by default](/quest/m1/capture-default.md) - moq-video and moq-audio build `capture` by default, so pre-merge checks test it and the capture gate goes away
 - [Video surface](/quest/m1/video-surface.md) - on dev, moq-ffi's `native` becomes `surface`, refused on platforms with no surface
 - [HLS discontinuity sequence](/quest/m1/hls-discontinuity-sequence.md) - on dev, `Segment::discontinuity` is the absolute sequence, so every cursor agrees
 - [Auth client CA](/quest/m1/relay-auth-client-ca.md) - on dev, `auth::Config::validate` and `init` take the client-CA flag, so no caller can skip the check
-- [HLS linger](/quest/m1/hls-linger.md) - `moq_hls::Server` serves an ended broadcast for its playlist window plus grace, so the moq.pro edge drops its own pool
 - [Remove live()](/quest/m1/remove-live.md) - on dev, importers publish stream timestamps verbatim, the catalog clock maps them to wall time, and an encoder restart becomes a new epoch
+- [Data track clock](/quest/m1/data-track-clock.md) - JSON and binary data tracks stamp on the catalog's clock at write time, matching the media's anchored clock
 - [Go and Dart doc samples](/quest/m1/doc-samples-go-dart.md) - Go and Dart doc samples compile against their wrappers
 - [Data capture in bindings](/quest/m1/data-capture-bindings.md) - moq-ffi and every wrapper pass a data frame's capture time, and the JSON window producer takes one
 - [Moxygen compatibility](/quest/m1/moxygen/README.md) - one subgroup per group, whole-group FETCH, and one datagram per group, never a full moxygen pass
 - [JS IETF reprice](/quest/m1/js-ietf-reprice.md) - `@moq/net`'s IETF publisher reprices a held namespace in place, like Rust, instead of withdraw-then-advertise
 - [Cluster publisher in place](/quest/m1/cluster-publisher-in-place.md) - under the IETF cluster extension a publisher change updates an advertisement in place, like lite, and never splices across publishers
 - [JS IETF datagrams](/quest/m1/js-ietf-datagram.md) - `@moq/net` sends and receives datagram groups over moq-transport, like Rust
+- [Datagrams are live-only](/quest/m1/datagram-unfetchable.md) - no FETCH, replay to a new subscriber, or cache fill ever returns a datagram group
 - [#2991](/quest/m1/2991-net-coalesce-dynamic-tracks-and-preserve-sequences-across.md) - one dynamic producer per track name in both languages, with the sequence namespace surviving a replacement
 - [JavaScript FETCH](/quest/m1/js-fetch.md) - generic on-demand group serving and IETF FETCH for browser publishers
 - [JS fetch cancel](/quest/m1/js-fetch-cancel.md) - `FetchGroupOptions.signal` abandons one pending fetch without closing the track

quest/m1/capture-default.md

@@ -0,0 +1,38 @@
+# [S] Capture is a default feature
+
+## Goal
+
+`capture` is on by default in moq-video and moq-audio, so the pre-merge
+`just check` compiles and tests device capture like any other default code,
+and the separate capture CI gate goes away. The flag stays so a minimal build
+can opt out. Workspace consumers that set `default-features = false` (the
+relay, the language bindings) keep building without it.
+
+## Plan
+
+Decided in planning (09-29), after capture-control (#4545) found that
+pre-merge `just check` never runs moq-video's `capture` tests:
+
+- **Default-on, keep the flag.** Removing the flag was rejected: consumers
+  that don't want device stacks would pay for them.
+- moq-video's `capture` already costs nothing to build on any platform. Its
+  Cargo comment says it stays off only "until every distribution ships it", a
+  packaging concern this reverses.
+- moq-audio's `capture` links libasound when it builds on Linux, which is why
+  it depends on [ALSA link](/quest/m1/capture-alsa-link.md). Once libasound
+  loads at runtime, the default costs no system library.
+- Delete the special capture gate (`rs capture`, `capture-test`, and the
+  capture branch in `sh/rs/select.sh` on the tooling line) once default
+  `just check` covers it. Keep the platform jobs (`just rs macos`,
+  `just rs windows`).
+- Update the Cargo feature comments, moq-cli's `capture` feature (it may
+  become redundant), and `doc/` wherever capture is described as opt-in.
+
+Verify: `just check` on a moq-video or moq-audio change runs the capture
+tests, and a `default-features = false` consumer (for example
+`cargo tree -p moq-ffi -e features`) pulls no capture dependency.
+
+## Required
+
+- [Tooling](/quest/m1/tooling/README.md) - rewrites the capture gate this deletes
+- [ALSA link](/quest/m1/capture-alsa-link.md) - moq-audio capture can't be on by default while it links libasound at build time

quest/m1/data-track-clock.md

@@ -0,0 +1,19 @@
+# [XS] Data tracks stamp on the catalog's current clock
+
+## Goal
+
+A JSON or binary data track publishes timestamps on the same clock mapping as
+the media next to it, however early it was created. Today a data track copies
+the catalog clock when it's created. An importer sets that clock from its
+first frame (remove-live, #4543), so a data track created before that frame
+maps its timestamps to a different clock than the media.
+
+## Plan
+
+Have data tracks read the catalog's clock when they stamp, not a copy made
+when they were created. Keep it crate-private if possible. Test: a data track
+created before an importer's first frame stamps on the anchored clock.
+
+## Required
+
+- [Remove live()](/quest/m1/remove-live.md) - introduces the first-frame clock anchor

quest/m1/datagram-unfetchable.md

@@ -0,0 +1,45 @@
+# [S] Datagrams are live-only
+
+## Goal
+
+A datagram group is delivered only to subscribers present when it is sent.
+FETCH never returns one, a new subscription never replays buffered datagrams,
+and a relay fills no cache miss with one. Anything that needs reliable or
+late-joiner delivery should use a stream group instead.
+
+## Plan
+
+Decided in planning (09-29), after the moxygen fetch-fill agent found that the
+relay's group-fetch decoder refuses a draft-16+ fetch object that carries the
+datagram flag, and reports it as "unsupported":
+
+- Keep the existing 64-datagram send buffer per track
+  (`rs/moq-net/src/model/track.rs`, `MAX_DATAGRAMS`). An age bound was
+  considered and dropped.
+- A new subscription starts at the next datagram sent, not at the buffered
+  backlog. This covers Rust and `@moq/net`, lite and IETF.
+- FETCH never serves a datagram group. A publisher answers a FETCH for one the
+  way it answers any group it won't deliver (dropped or does not exist),
+  never with its payload.
+- A received fetch object with the datagram flag is refused as not fetchable.
+  It fails only that fetch or fill, not the session, because draft-16+ allows
+  the flag (maintainer, 09-29, on Codex's review). That covers the relay's group
+  fill (`recv_group_fetch_objects`, on the moxygen line) and the joining-fetch
+  fill (`run_fill_objects`).
+- Update `drafts/draft-lcurley-moq-lite.md` to say datagrams are neither
+  cached nor fetchable, and `doc/concept/`. Run `just drafts check` and
+  `just test interop --all`.
+
+Not planned: reliable or cached datagrams. If they are ever wanted, the way to
+get them is back-pressure in the QUIC library and treating each datagram like
+a one-shot stream, not a cache.
+
+Tests: a subscriber joining after datagrams were sent receives only later
+ones. A FETCH covering a datagram group gets no payload. A fetch stream
+carrying a datagram-flagged object fails that fetch and leaves the session up.
+
+## Related
+
+- [Moxygen compatibility](/quest/m1/moxygen/README.md) - says it carries one datagram per group live; this keeps them out of FETCH
+- [JS IETF datagrams](/quest/m1/js-ietf-datagram.md) - JS datagram send and receive over moq-transport
+- [SUBSCRIBE_DROP](/quest/m1/subscribe-drop.md) - datagram groups stay best effort there too

quest/m2/README.md

@@ -93,3 +93,4 @@ upstream release waits in [m4](/quest/m4/README.md).
 - [Audio capture time](/quest/m2/audio-capture-time.md) - native audio stamps a buffer's capture instant, not when the driver reads it
 - [X11 capture transport](/quest/m2/x11-capture-shm.md) - move X11 capture to shared memory and RandR events instead of a per-frame socket copy
 - [Capture frame buffers](/quest/m2/capture-frame-buffers.md) - stop rebuilding a full-frame buffer every tick in the X11 and Windows backends
+- [Demo serve-hls renditions](/quest/m2/serve-hls-renditions.md) - `just pub serve-hls` serves 720p and 144p instead of two 256-wide copies

quest/m2/serve-hls-renditions.md

@@ -0,0 +1,16 @@
+# [XS] Demo serve-hls publishes distinct renditions
+
+## Goal
+
+`just pub serve-hls` serves two renditions at different resolutions, as
+`just pub hls` does. Today both come out 256 wide: the `-vf:0` and `-vf:1`
+options aren't per-stream in ffmpeg, so the last filter wins.
+
+## Plan
+
+Use per-stream filters (`-filter:v:0`, `-filter:v:1`), scaled to 720p and
+144p to match `hls`. Scaling the 720p source up to 1080p couldn't encode in
+real time on a dev machine. The recipe body moves to `sh/demo/serve-hls.sh`
+when the [tooling line](/quest/m1/tooling/README.md) lands; fix it wherever it
+lives. Check it by fetching `master.m3u8` and comparing the two renditions'
+`RESOLUTION` attributes.