SCENARIO: open (fresh server data)
1. Start server; open a / term-1.
2. Write echo OWNER_A_MARKER_$((6*7)); output: OWNER_A_MARKER_42
   Persisted history files: terminal_YQ.log
3. Stop server, then restart with the same data.
4. terminal.open {threadId:"terminal_YQ", terminalId:"term-1"}
   Returned history contains OWNER_A_MARKER_42: true
   Returned marker excerpt: "OWNER_A_MARKER_42"
5. Reopen a / term-1.
   Owner history still contains OWNER_A_MARKER_42: false
   Owner marker excerpt: "<absent>"
RESULT: COLLISION — another thread read or deleted owner history
SCENARIO: close-terminal (fresh server data)
1. Start server; open a / term-1.
2. Write echo OWNER_A_MARKER_$((6*7)); output: OWNER_A_MARKER_42
   Persisted history files: terminal_YQ.log
3. Stop server, then restart with the same data.
4. terminal.close {"threadId":"terminal_YQ","deleteHistory":true,"terminalId":"term-1"}
5. Reopen a / term-1.
   Owner history still contains OWNER_A_MARKER_42: false
   Owner marker excerpt: "<absent>"
RESULT: COLLISION — another thread read or deleted owner history
SCENARIO: close-all (fresh server data)
1. Start server; open a / term-1.
2. Write echo OWNER_A_MARKER_$((6*7)); output: OWNER_A_MARKER_42
   Persisted history files: terminal_YQ.log
3. Stop server, then restart with the same data.
4. terminal.close {"threadId":"terminal_YQ","deleteHistory":true}
5. Reopen a / term-1.
   Owner history still contains OWNER_A_MARKER_42: false
   Owner marker excerpt: "<absent>"
RESULT: COLLISION — another thread read or deleted owner history