peggy
7a2639d0f4
ci/woodpecker/pr/ci Pipeline was successful
When MOSAIC_AGENT_NAME is unset and the sender has no tmux client context ($TMUX empty), agent-send.sh fell back to 'tmux display-message -p #S', which outside tmux reports the LAST-ACTIVE session on the server. A nameless sender was silently stamped as whichever seat touched tmux most recently, forging that seat's identity in the preamble. Incident (2026-08-20, host sb-it-1-dt): a nameless non-tmux sender was stamped 'peggy', a live seat, on a message delivered TO peggy. Reproduced end-to-end before the fix; capture in the seat evidence note. Fix: the display-message fallback now runs only when $TMUX is set (inside tmux it resolves the caller's own session — the case #808 built it for). Outside tmux with no name, the label is host:unverified. Deliberate identity remains available via -S. Chosen over refusing the send: nameless senders are legitimate; the defect was borrowing an identity, not lacking one. Tests: suite made hermetic (TMUX controlled explicitly; results no longer depend on the caller's context — previously tests 9/10 inherited the caller's TMUX). New case 9b: no-tmux sender is labeled unverified and never a borrowed name (red on original: host:local-agent borrowed from the fake tmux server; green after). 19/19 in both caller contexts.