C1: Box<dyn TtyControl + Clone> does not compile (Clone is not object-safe).
Replace with a TtyControlHandle newtype: #[derive(Clone)] wrapping
Arc<dyn TtyControl + Send + Sync>. The trait stays object-safe; the
newtype carries the Clone-ability. Updated across tty-backend.md,
ADR-053, OQ-43, and the tty README.
W1: 'Drop is the cleanup, threads exit on channel close' was false for
the local PTY waiter thread (blocked in Child::wait(), does not observe
channel close) — a child that ignores stdin EOF would be orphaned on
session cancel. New ADR-056 commits a backend cleanup contract: dropping
the exit_code future MUST kill the session target. The local backend
implements it via a ChildKiller held in the exit_code future's Drop
guard (disarmed on resolve). Corrected the lifecycle section in
tty-adapter.md, added the mechanism + constraint to tty-local.md, and
referenced ADR-056 from tty-backend.md, overview.md, both READMEs.
S1: error-frame < 16 MiB stated as a wire-format invariant (not an
assumption) so the 0x00-first-byte disambiguation trick is sound by
construction.
S2: carriage field validation (MUST be "raw" in v1, else
malformed_negotiation) specified.
S3: NegotiateRequest + TerminalParamsWire Rust structs added with
serde defaults and validation rules.
S4: modes field annotated 'backends MUST ignore content in v1' in both
tty-backend.md and ADR-053.
S5: AsyncWrite/Stream qualified with crate origins (tokio::io,
futures_core) in the TtyHandle struct definitions.
The backpressure chain is complete by construction: QUIC flow control
→ bounded drainer channel → bounded stdout channel → OS pipe/PTY buffer
→ process write() blocks. Every link awaits its producer; no unbounded
buffer breaks the chain. The reversal path (an additive ControlMessage
variant, not a wire-format header change) is noted in ADR-052's
consequences as a two-way door, not the expected path.
Tightened ADR-052 assumption 1 from a hedge ('expected to work; a POC
would confirm') to a decided constraint. Updated all OQ-45 references
across the tty spec docs from 'open (low risk)' to 'resolved'.
Establishes the tasks/architecture/ blocker-task half of the Safe Exit
protocol. Each deferred OQ now has an external-trigger tracker task
representing its unblocking condition, and the OQ's Blocked on field names
the tracker task ID — closing the gap where the deferral field existed but
the task-graph half was unenforced.
Changes:
- Add 6 external-trigger tracker tasks for the deferred OQs (OQ-09, 10, 32,
41, 44, 46) under tasks/architecture/, tagged [external-trigger, deferred-oq]
- Add structured Blocked on field to OQ-09 and OQ-10 (previously used legacy
'deferred' status with the reason in the Resolution prose); index now
surfaces all 6 deferred OQs with concrete conditions, no placeholders
- Document the architecture-task level mapping (level: implementation for
ADRs/specs, decomposition for spec-to-ADR breakdown, planning for backlog
seeding, research/review direct fits) and the deferred-OQ blocker-task
pattern in docs/sdd_process.md
- Mark architecture/safe-exit-blocker-task-mechanism and
architecture/oq-09-10-blocking-conditions completed (implemented by this pass)
- Fix 4 pre-existing ADR-050 implementation tasks: status: done → completed
(taskgraph enum is 'completed', not 'done') — taskgraph validate now passes
for all 100 tasks
The monolithic open-questions.md (1310 lines, 47 OQs) was large enough to be
unmanageable, with high size variance (OQ-42 at 220 lines next to OQ-06 at 8).
Decomposed into one file per OQ under docs/architecture/questions/ (NNN-slug.md,
mirroring the ADR convention), with open-questions.md retained as the index:
theme-grouped tables plus a cross-theme Deferred/Blocked section that surfaces
the 6 deferred OQs with their Blocked-on conditions inline (the safe-exit
visibility surface). Per-OQ content moved verbatim; all 62 inbound links stay
valid (none used anchors). README's curated OQ summary dropped (now redundant
with the index tables).
Also seeds tasks/architecture/ with this task plus two follow-ups found during
the decompose: OQ-09/10 missing structured Blocked-on fields, and the
tasks/architecture/ blocker-task half of the Safe Exit protocol being
unenforced.
glm-5.2