Design Counsel — Terminal Session Ownership

Three review rounds across two models, an adversarial fact-check, and a close-out · the design that emerged is not the one I proposed

1 · How the counsel ran

Process and convergence⤢ zoom

The GPT seat returned nothing in all three rounds and was dropped. Grok ran through its CLI; the wrapper was instructed to report a failure rather than author findings, so its participation is real rather than assumed. Findings fell 10 → 6 → 5 and 8 → 7 → 5 across rounds — converging, not exhausted.

2 · The live bug

Four independently reasonable decisions compose into a shell-killer.

Detach a pane → duplicate agent⤢ zoom

The error string says the PTY was not found. It was found — that is how its identity got compared. The word “not found” is doing double duty for “absent” and “present but mismatched”, and a regex cannot tell them apart.

// my classifier — the last link
export function isProvenSshSessionGoneError(error: unknown): boolean {
  if (message.includes(SSH_SOURCE_RESTORE_REQUIRED_ERROR)) return false
  return message.includes(SSH_SESSION_EXPIRED_ERROR) || /PTY ".+" not found/i.test(message)
}
// two functions away, unused by me:
export function isSshPtyIdentityMismatchError(error: unknown): boolean

The gate is on the wrong path

I shipped “respawn requires positive proof” and pinned it with a test. Grok traced every respawn path and found the proof check is bypassed on the main one, because the error never reaches a classifier — it is converted into a boolean first:

// pty-transport.ts — catches the error and RESOLVES
return { id: options.sessionId, sessionExpired: true }

// pty-connection.ts — respawns on the flag alone, no proof check
if (connectResult?.sessionExpired) { /* clear binding */
  startFreshColdRestoreAgentResume(...) }

Respawn paths vs the proof gate⤢ zoom

3 · What the counsel changed about my design

My proposal	Counsel’s design	Why theirs is better
Two records: ownership + orphan inventory	One record. Orphans become a connect-time projection with no durable rows	A durable orphan row goes stale across exactly the disconnect during which the truth changed — and an orphan is only actionable while connected. Also deletes the two-record transaction my split needed.
Key by paneKey = tabId:leafId	Key by leafId; tab derived from the live layout, never stored	A stored tabId is either frozen (names a tab the leaf left) or updated (desyncs from the relay’s copy). Both are live failures. Keying by the leaf deletes the transfer problem instead of managing it.
Keep attach-time pane identity	Delete it — compare returned incarnation instead	The apparatus is over-strict and under-strict at once: it rejects a live renamed pane, and accepts a different shell after a relay restart recycles the id. It fails at its own stated job.
“Unknown is not dead” as a principle	Same rule, made structural: fate must be reported by the host, never inferred from timing, absence, or error-string shape	Every defect found across three rounds is one violation of that clause. Mine was a slogan; theirs is a rule with an enforcement point.

Both models proposed the single-record collapse independently, which is the strongest signal available in a counsel and why it outweighed my version.

4 · The rule everything follows from

Ownership vs fate⤢ zoom

This is what makes the offline case work without an authority layer. Ownership is answerable with the network down, because it never depended on the network. Fate is never answered by the client at all.

5 · The record

/** Main-owned. TOP-LEVEL in PersistedState — never inside WorkspaceSessionState. */
type PaneShellOwnership = {
  leafId: string          // PRIMARY KEY — layout leaf UUID
  hostId: ExecutionHostId // FIELD: 'local' | 'ssh:<target>' | 'runtime:<id>'
  worktreeId: string
  ptyId: string           // relay-native form for SSH — one namespace, always
  incarnationId: string   // REQUIRED
  relayInstanceId?: string
  state: 'attached' | 'detached' | 'terminated'
  createdAt / updatedAt / lastAttachedAt? / lastDetachedAt?
}
// Absent on purpose: no tabId, no paneKey, no hostEpoch, no second record.

Uniqueness is enforced on (hostId, ptyId, incarnationId), not ptyId alone — because relay ids are minted pty-1, pty-2… per relay process, so pty-1 recurs on every host after every relay restart. Round 1 had rejected a collision here as impossible; round 3 showed it is guaranteed, and the rejection was withdrawn.

6 · Orphans are a projection, not an authority

Why no durable orphan rows⤢ zoom

7 · What gets deleted

Deleted	Where
Attach-identity apparatus	relay comparison + throw, the error constants, the expected-identity derivation on both reattach paths, the renderer branch that treats a mismatch as proof
Lease↔binding reconciliation	supersession, ranking, deferral, rollback, dual matchers — the ~209 lines I added, plus the ~374 that preceded them
The restorable fork	the two contradictory predicates where absence of a lease meant opposite things depending on a sibling leaf
The 30-second grant arithmetic	replaced by an explicit record state
Never built at all	hostEpoch and its clock arithmetic; a five-row evidence matrix; a resumed flag — all proposed in earlier rounds and killed before implementation

8 · Verification

Models assert plausible file contents confidently, so every claim about existing code was checked.

Eleven of the twelve errors were citation-level and changed no conclusion. One was a real premise defect: the claim that abandoning a wrongly-attached shell is free. It is not — attach commits activation, clears pending output and may replay before it returns the incarnation the client would use to detect the mistake, and there is no detach RPC to undo it. That correction is folded in as C4.

I independently verified the duplicate-agent chain end to end, since it implicates my own code.

9 · Where the models disagreed

Conflict	Status
Do shells survive a hard relay death on Windows/WSL?	Open — adjudicated toward “dead” on POSIX evidence; the Windows case is not established
Does the 30-second recovery grant execute in production at all?	Open — two reviewers read its comparison as unreachable for a real SSH pane; the covering test seeds a shape production cannot produce
Should relayInstanceId exist?	Open — one would delete it and let incarnation carry the rule; the other keeps it because a re-minted id proves only that the relay restarted
Fix or delete the attach identity?	Resolved — deletion, and the synthesizer went further than either reviewer

10 · Readiness

A final pass re-checked whether the close-out actually closed its own blockers. Verdict: STILL NOT READY.

Blocker	Close-out
The spawn reattach path still wraps any not-found as expired, so client-side auto-respawn survives	NOT CLOSED — C1 hardens the classifier, but the primary path never reaches a classifier. Every auto-respawn consumer must require proof, not just the one that catches a throw.
Migrated records have no incarnation, but the design requires one and throws on mismatch	CLOSED, conditionally — C2/C3 work only if an absent recorded incarnation means learn and stamp, never mismatch. That rule must be written into both the algorithm and the type.

11 · Decisions for you

#	Decision
1	The live bug. It is independent of the redesign and fixable in isolation. Fix it now as its own change, or fold it into the track?
2	Visible detached panes. The design replaces an invisible 30-second auto-recovery with an explicit state and two actions (reattach / start a new shell). That is a deliberate product change — a user-initiated relay reset would now show detached panes rather than silently recreating shells.
3	Release policy. A leaf removed while its shell lives releases the claim — the shell becomes orphan-eligible and adoptable, and is never auto-killed. Confirm you want liveness preserved over tidiness.
4	Sequencing. Two preconditions block everything: one partition per (target, pane), and one bind producer. The second is also what would make the shipped fence non-inert.