test(ssh): scope the relay liveness double's invalidation to one PTY

The double invalidated every pending live evidence on any exit, while the real
SshPtyLivenessState invalidates only the exiting PTY's. Nothing is vacuous
today because each test uses one PTY, but a two-PTY test would pass here and
fail in production.

src/main/ssh/ssh-relay-session-incarnation.test.ts

@@ -51,7 +51,7 @@ vi.mock('../agent-hooks/remote-managed-hook-installers', () => ({
 }))
 vi.mock('../providers/ssh-pty-provider', () => ({
   SshPtyProvider: class MockSshPtyProvider {
-    private readonly pendingLiveEvidence = new Set<{ valid: boolean }>()
+    private readonly pendingLiveEvidence = new Map<string, Set<{ valid: boolean }>>()
     readonly providerGeneration: number
     onData = vi.fn().mockReturnValue(() => {})
     onReplay = vi.fn().mockReturnValue(() => {})
@@ -59,32 +59,34 @@ vi.mock('../providers/ssh-pty-provider', () => ({
     attach = vi.fn().mockResolvedValue(undefined)
     attachForReconnect = vi.fn().mockResolvedValue({})
     acceptLivePty = vi.fn()
-    beginLivePtyEvidence = vi.fn(() => {
+    beginLivePtyEvidence = vi.fn((id: string) => {
       const evidence = { valid: true }
-      this.pendingLiveEvidence.add(evidence)
+      const pending = this.pendingLiveEvidence.get(id) ?? new Set<{ valid: boolean }>()
+      pending.add(evidence)
+      this.pendingLiveEvidence.set(id, pending)
       return evidence
     })
     settleLivePtyEvidence = vi.fn(
       (id: string, evidence: { valid: boolean }, acceptLive: boolean) => {
-        this.pendingLiveEvidence.delete(evidence)
+        this.pendingLiveEvidence.get(id)?.delete(evidence)
         if (evidence.valid && acceptLive) {
           this.acceptLivePty(id)
         }
       }
     )
-    acceptUnverifiablePty = vi.fn((_id: string) => {
-      for (const evidence of this.pendingLiveEvidence) {
+    // Mirrors SshPtyLivenessState: only the named PTY's pending live evidence is invalidated.
+    acceptUnverifiablePty = vi.fn((id: string) => {
+      for (const evidence of this.pendingLiveEvidence.get(id) ?? []) {
         evidence.valid = false
       }
-      this.pendingLiveEvidence.clear()
+      this.pendingLiveEvidence.delete(id)
     })
     acceptAmbiguousExitPty = vi.fn((id: string) => this.acceptUnverifiablePty(id))
-    // Mirrors SshPtyLivenessState.acceptExited, which invalidates pending live evidence.
-    acceptExitedPtyLiveness = vi.fn((_id: string) => {
-      for (const evidence of this.pendingLiveEvidence) {
+    acceptExitedPtyLiveness = vi.fn((id: string) => {
+      for (const evidence of this.pendingLiveEvidence.get(id) ?? []) {
         evidence.valid = false
       }
-      this.pendingLiveEvidence.clear()
+      this.pendingLiveEvidence.delete(id)
     })
     acceptExitedPty = vi.fn()
     dispose = vi.fn()