A peer session consolidated branches onto master (6678acd1) and landed work in the
same two files this branch was changing, so it flagged the collision early. Merged
now, while both sides' intent is still known, rather than later from the diff alone.

Both conflicts were purely additive — each side had inserted different code at the
same seam — so both sides are kept:

- launchers.py: my spawn guard (pidfile + identity re-check + per-decision logging,
  3c00a9cb) sits alongside their `_clear_latch()`. These compose correctly and are
  about opposite problems: mine refuses to start a SECOND instance, theirs clears
  the "the human closed this" latch when a start is deliberate. Their
  `_clear_latch(spec)` call inside `launch()` merged cleanly into my rewritten
  version of that function.
- midiviz.py: their close-latch block (`latch_close_path`, `_latch_close`) plus MY
  `build_widget` signature, which carries the `pinned_port`/`watch` parameters the
  replug-resilience work added (e9d16314). Their side's copy of that def line was
  the older two-arg form and was dropped in favour of mine.

Verified in an isolated worktree, not in the shared checkout — that tree holds the
peer's uncommitted edits to check-mix.py and gig-log.py, and merging there would
have demanded I stash another session's in-flight work. Two untracked files of
theirs were moved aside to let git proceed and restored byte-identical afterwards.

  pytest tools/tests tools/bridge/tests armada/tide-table -> 476 passed
  midiviz --selftest -> PASS (parsed=68 ingested=253 paints=172, 163 colours)

Both of the features that had to survive this merge do: the surviving grep shows
the spawn guard, the pending sweep, the latch clear, the close X, the pin toggle,
the reconnect timer and the hardware-vs-phantom port discrimination all present.