quest(m1): plan the TS repeated-tables fix

quest/m1/README.md

@@ -173,6 +173,7 @@ bench all require its crate.
 - [T-STD TS export](/quest/m1/tstd/README.md) - `moq export ts` is a proper remux that passes the T-STD buffer model, starting with a fixed `--delay`
 - [Multi-packet PMT](/quest/m1/ts-pmt-split.md) - `export ts` splits a PMT longer than one packet instead of exiting before its first packet
 - [ATSC AC-3](/quest/m1/ts-atsc-ac3.md) - `export ts` carries 48 kHz ATSC AC-3 at every A/52 rate up to 640 kb/s instead of aborting from 384 kb/s up
+- [TS table bursts](/quest/m1/ts-psi-repeat.md) - `export ts` lays a repeated PAT and PMT once where aligned keyframes would bunch them past their transport buffer
 - [TS damage log](/quest/m1/ts-damage-log.md) - a burst of damaged TS units logs a first warning and a periodic summary per PID, not one warning per unit
 - [TS adaptation field length](/quest/m1/ts-adaptation-only.md) - a TS adaptation field with the wrong length for its packet (183 adaptation-only, at most 182 with a payload) is refused as damage
 - [Rust non-continuous signal](/quest/m1/rust-continuous.md) - the Rust container consumer reports a frame after a subscribe or discontinuity as non-continuous, like JS, for the tune-in and warmup trims

quest/m1/ts-psi-repeat.md

@@ -0,0 +1,44 @@
+# [M] TS export never bunches repeated program tables
+
+## Goal
+
+`moq export ts` never lays copies of the program tables back to back where
+they would overrun the PAT's or a PMT's 512-byte transport buffer, drained at
+Rxsys = 1 Mb/s (ISO 13818-1 2.4.2.3). Every copy that marks its own tune-in
+point still goes out, and changed tables still go out in order. Export carries
+every video rendition and writes the tables ahead of each video keyframe, so an
+ABR ladder of three or more renditions with aligned keyframes overruns the
+PAT's buffer today. At 25 Mb/s, three PAT and PMT pairs back to back deliver
+564 B of PAT in about 301 µs, of which about 38 B drains, peaking near 526 B.
+Two renditions' 376 B fit.
+`compliance.py` grades the program tables' buffers too, so every TS Interop arm
+catches a regression.
+
+## Plan
+
+Decided (2026-10-10), from Codex's review of #5207 and kixelated's reply
+there. `Slot::layout` (`rs/moq-mux/src/container/ts/schedule.rs`) lays the
+tables just ahead of the first packet muxed after them, so when a heavier lane
+goes first, every table group in the slot flushes at once. `main` bunched them
+the same way at high fill before #5207.
+
+- Start from the diff in
+  [the review thread](https://github.com/moq-dev/moq/pull/5207#discussion_r4239051134):
+  a run of tables that the same flush would lay right behind an identical run
+  is dropped and padded back with nulls at the end of a padded slot, and
+  `Slot::nulls` becomes `Option<usize>` so an unpadded slot gains none. A slot
+  still opens with its clock packet and keeps its length, so no PCR moves.
+  Carrying each table once per slot was tried and reverted in #5207: it dropped
+  the copies that lead each send-ahead unit, breaking the tune-in points
+  `aac_program_config_follows_each_table` checks.
+- A new table version that bunches with the old one stays as rare as it is;
+  spacing it out is not in scope.
+- `compliance.py` gains a hard system-buffer check for the PAT and every PMT
+  PID: TBsys of 512 B drained at Rxsys, then Bsys, per ISO 13818-1 2.4.2.3. Its
+  strict T-STD check models only elementary streams today. DVB SI (SDT, EIT)
+  and SCTE-35 stay out, since ISO defines those buffers for program-specific
+  information. Every existing TS arm still passes.
+- Test: a unit test runs laid slots' PAT and each PMT PID through its own
+  512-byte buffer drained at 1 Mb/s, with keyframes aligned at 25 Mb/s on three
+  video PIDs, which fails without the fix, and on two, which passes either way;
+  plus the diff's `a_repeated_table_run_is_laid_once`.